Mallinckrodt (MNKTQ) 10-Q4 May 212021 Q1 Quarterly reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
Document And Entity Information - shares	Mar. 26, 2021	Apr. 30, 2021
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-35803
Entity Registrant Name	Mallinckrodt plc
Entity Incorporation, State or Country Code	L2
Entity Tax Identification Number	98-1088325
Entity Address, Address Line One	College Business & Technology Park
Entity Address, City or Town	Dublin
Entity Address, Postal Zip Code	15
Entity Address, Country	IE
City Area Code	1
Local Phone Number	696 0000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Central Index Key	0001567892
Current Fiscal Year End Date	--12-31
Document Period End Date	Mar. 26, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Ordinary Shares Outstanding		84,709,114
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Address, Address Line Two	Cruiserath
Entity Address, Address Line Three	Blanchardstown
Country Region	353
Entity Filer Category	Accelerated Filer

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 26, 2021	Mar. 27, 2020
Net sales	$ 558	$ 665.8
Cost of sales	307.6	382
Gross profit	250.4	283.8
Selling, general and administrative expenses	136	231.1
Research and development expenses	66.2	77.4
Restructuring charges, net	0.4	(1.8)
Non-restructuring impairment charges	64.5	0
Losses on divestiture	0.8	0.2
Opioid-related litigation settlement gain (Note 11)	0	(16.8)
Operating loss	(17.5)	(6.3)
Interest expense	(59.6)	(74.5)
Interest income	1.9	3.5
Other income, net	8.1	1.7
Reorganization Items	(93.5)	0
Loss from continuing operations before income taxes	(160.6)	(75.6)
Income tax benefit	(16.4)	(18.9)
Loss from continuing operations	(144.2)	(56.7)
Income from discontinued operations, net of income taxes	0.3	6.5
Net loss	$ (143.9)	$ (50.2)
Basic loss per share (Note 5):
Loss from continuing operations	$ (1.70)	$ (0.67)
Income from discontinued operations	0	0.08
Net loss	$ (1.70)	$ (0.60)
Basic weighted-averaged shares outstanding (in shares)	84.6	84.2
Diluted loss per share (Note 5):
Loss from continuing operations	$ (1.70)	$ (0.67)
Income from discontinued operations	0	0.08
Net loss	$ (1.70)	$ (0.60)
Diluted weighted-average shares outstanding (in shares)	84.6	84.2
Retained Earnings (Deficit)
Net loss	$ (143.9)	$ (50.2)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2021	Mar. 27, 2020
Net loss	$ (143.9)	$ (50.2)
Other comprehensive income (loss), net of tax:
Currency translation adjustments	0.2	(1.1)
Benefit plans, net of tax	(0.1)	(0.2)
Total other comprehensive income (loss), net of tax	0.1	(1.3)
Comprehensive loss	$ (143.8)	$ (51.5)

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 26, 2021	Dec. 25, 2020
Current Assets:
Cash and cash equivalents	$ 1,077.9	$ 1,070.6
Accounts receivable, less allowance for doubtful accounts of $4.0 and $4.5	477.4	538.8
Inventories	363.4	344.9
Prepaid expenses and other current assets	367.9	350
Total current assets	2,286.6	2,304.3
Property, plant and equipment, net	794.4	833.1
Intangible assets, net	5,974.7	6,184.5
Other assets	380.5	393.5
Total Assets	9,436.2	9,715.4
Current Liabilities:
Current maturities of long-term debt	1,701.7	3,587.9
Accounts payable	98.4	93.3
Accrued payroll and payroll-related costs	80.4	79.4
Accrued interest	27.8	26.9
Accrued and other current liabilities	357.2	331.2
Total current liabilities	2,265.5	4,118.7
Pension and postretirement benefits	33.6	34.6
Environmental liabilities	59	59.8
Deferred Tax Liabilities, Gross	77.2	80.6
Other income tax liabilities	106.7	100.1
Other liabilities	101.1	109.8
Liabilities Subject to Compromise	5,914.2	4,192.6
Total Liabilities and Shareholders' Equity	9,436.2	9,715.4
Other liabilities	8,557.3	8,696.2
Shareholders' Equity:
Preferred shares	$ 0	$ 0
Preferred shares, shares outstanding (in shares)	0	0
Ordinary A shares	$ 0	$ 0
Ordinary shares	18.8	18.8
Ordinary shares held in treasury at cost	(1,616.1)	(1,616.1)
Additional paid-in capital	5,591.1	5,587.6
Retained deficit	(3,105.4)	(2,961.5)
Accumulated other comprehensive loss	(9.5)	(9.6)
Total Shareholders' Equity	$ 878.9	$ 1,019.2
Ordinary A
Shareholders' Equity:
Ordinary A shares, shares outstanding (in shares)	0	0

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) $ in Millions	Mar. 26, 2021€ / shares	Mar. 26, 2021USD ($)$ / sharesshares	Dec. 25, 2020€ / shares	Dec. 25, 2020USD ($)$ / sharesshares
Allowance for doubtful accounts \| $		$ 4		$ 4.5
Preferred shares, par value (in usd per share) \| $ / shares		$ 0.20		$ 0.20
Preferred shares, shares authorized (in shares)		500,000,000		500,000,000
Preferred shares, shares issued (in shares)		0		0
Preferred shares, shares outstanding (in shares)		0		0
Ordinary shares, par value (in usd per share) \| $ / shares		$ 0.20		$ 0.20
Ordinary shares, shares authorized (in shares)		500,000,000		500,000,000
Ordinary shares, shares issued (in shares)		94,145,367		94,111,303
Ordinary shares, shares outstanding (in shares)		84,627,154		84,605,156
Ordinary shares held in treasury at cost (in shares)		9,518,213		9,506,147
Ordinary A
Ordinary shares, par value (in usd per share) \| € / shares	€ 1		€ 1
Ordinary shares, shares authorized (in shares)		40,000		40,000
Ordinary shares, shares issued (in shares)		0		0
Ordinary A shares, shares outstanding (in shares)		0		0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2021	Mar. 27, 2020
Cash Flows From Operating Activities:
Net loss	$ (143.9)	$ (50.2)
Adjustments to reconcile net cash from operating activities:
Depreciation and amortization	169.6	223.1
Share-based compensation	3.6	6.7
Deferred income taxes	(3.4)	5.5
Non-cash impairment charges	64.5	0
Reorganization Items, non-cash	15.7	0
Other non-cash items	(11.9)	(19.4)
Changes in assets and liabilities, net of the effects of acquisitions:
Accounts receivable, net	61.8	49.4
Inventories	(22.8)	(18.4)
Accounts payable	0.5	(22.9)
Income taxes	(21.2)	(34.9)
Other	38.9	(85.2)
Net Cash From Operating Activities	151.4	53.7
Cash Flows From Investing Activities:
Capital expenditures	(20.9)	(19.9)
Other	(0.7)	3.2
Net Cash From Investing Activities	(21.6)	(16.7)
Cash Flows From Financing Activities:
Repayment of external debt	(118.9)	(4.9)
Payments of Financing Costs	0	4
Debt financing costs	0	(4)
Net Cash Provided From Financing Activities	(118.9)	(8.9)
Effect of currency rate changes on cash	(0.4)	(1.5)
Net change in cash, cash equivalents and restricted cash	10.5	26.6
Cash, cash equivalents and restricted cash at beginning of period	1,127	822.6
Cash, cash equivalents and restricted cash at end of period	1,137.5	849.2
Cash and cash equivalents, end of period	1,077.9	808
Restricted Cash and Investments, Current	23.4	5.4
Restricted Cash and Investments, Noncurrent	36.2	35.8
Retained Earnings (Deficit)
Cash Flows From Operating Activities:
Net loss	$ (143.9)	$ (50.2)

Condensed Consolidated Statem_4

Condensed Consolidated Statement of Changes in Shareholders' Equity Statement - USD ($) $ in Millions	Total	Ordinary Shares	Treasury Shares	Additional Paid-In Capital	Retained Earnings (Deficit)	Accumulated Other Comprehensive Loss
Shares, Outstanding		93,500,000	9,400,000
Beginning balance at Dec. 27, 2019	$ 1,940.7	$ 18.7	$ (1,615.7)	$ 5,562.5	$ (2,016.9)	$ (7.9)
Net loss	(50.2)				(50.2)
Other Comprehensive Income (Loss), Net of Tax	(1.3)					(1.3)
Vesting of restricted shares (in shares)		100,000	0
Vesting of restricted shares (in usd)	(0.1)	$ 0	$ 0	(0.1)
Share-based compensation	6.7			6.7
Ending balance at Mar. 27, 2020	$ 1,895.8	$ 18.7	$ (1,615.7)	5,569.1	(2,067.1)	(9.2)
Shares, Outstanding		93,600,000	9,400,000
Shares, Outstanding		94,100,000	9,500,000
Beginning balance, ordinary shares (in shares) at Dec. 25, 2020	94,111,303
Beginning balance, treasury shares (in shares) at Dec. 25, 2020	9,506,147
Beginning balance at Dec. 25, 2020	$ 1,019.2	$ 18.8	$ (1,616.1)	5,587.6	(2,961.5)	(9.6)
Net loss	(143.9)				(143.9)
Other Comprehensive Income (Loss), Net of Tax	0.1					0.1
Vesting of restricted shares (in shares)		0	0
Vesting of restricted shares (in usd)	(0.1)	$ 0	$ 0	(0.1)
Share-based compensation	$ 3.6			3.6
Ending balance, ordinary shares (in shares) at Mar. 26, 2021	94,145,367
Ending balance, treasury shares (in shares) at Mar. 26, 2021	9,518,213
Ending balance at Mar. 26, 2021	$ 878.9	$ 18.8	$ (1,616.1)	$ 5,591.1	$ (3,105.4)	$ (9.5)
Shares, Outstanding		94,100,000	9,500,000

Background and Basis of Present

Background and Basis of Presentation	3 Months Ended
Background and Basis of Presentation	Mar. 26, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	1. Background and Basis of Presentation Background Mallinckrodt plc is a global business of multiple wholly owned subsidiaries (collectively, "Mallinckrodt" or "the Company") that develop, manufacture, market and distribute specialty pharmaceutical products and therapies. Areas of focus include autoimmune and rare diseases in specialty areas like neurology, rheumatology, nephrology, pulmonology and ophthalmology; immunotherapy and neonatal respiratory critical care therapies; analgesics and gastrointestinal products. The Company operates in two reportable segments, which are further described below: • Specialty Brands includes innovative specialty pharmaceutical brands; and • Specialty Generics includes niche specialty generic drugs and active pharmaceutical ingredients ("API(s)"). The Company owns or has rights to use the trademarks and trade names that are used in conjunction with the operation of its business. One of the more important trademarks that the Company owns or has rights to use that appears in this Quarterly Report on Form 10-Q is "Mallinckrodt," which is a registered trademark or the subject of pending trademark applications in the United States ("U.S.") and other jurisdictions. Solely for convenience, the Company only uses the ™ or ® symbols the first time any trademark or trade name is mentioned in the following notes. Such references are not intended to indicate in any way that the Company will not assert, to the fullest extent permitted under applicable law, its rights to its trademarks and trade names. Each trademark or trade name of any other company appearing in the following notes is, to the Company's knowledge, owned by such other company. Basis of Presentation The unaudited condensed consolidated financial statements have been prepared in U.S. dollars and in accordance with accounting principles generally accepted in the U.S. ("GAAP"). The preparation of the unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities, disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses. Actual results may differ from those estimates. The unaudited condensed consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries and entities in which they own or control more than 50.0% of the voting shares, or have the ability to control through similar rights. All intercompany balances and transactions have been eliminated in consolidation and all normal recurring adjustments necessary for a fair presentation have been included in the results reported. The results of entities disposed of are included in the unaudited condensed consolidated financial statements up to the date of disposal, and where appropriate, these operations have been reported in discontinued operations. Divestitures of product lines and businesses not meeting the criteria for discontinued operations have been reflected in operating loss. The fiscal year end balance sheet data was derived from audited consolidated financial statements, but do not include all of the annual disclosures required by GAAP; accordingly these unaudited condensed consolidated financial statements should be read in conjunction with the Company's audited annual consolidated financial statements included in its Annual Report on Form 10-K for the fiscal year ended December 25, 2020 filed with the U.S. Securities and Exchange Commission ("SEC") on March 10, 2021. Certain prior-period amounts on the unaudited condensed consolidated financial statements have been reclassified to conform to current-period presentation. Voluntary Filing Under Chapter 11 and Going Concern The accompanying unaudited condensed consolidated financial statements are prepared in accordance with GAAP applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. On October 12, 2020, Mallinckrodt plc and certain of its subsidiaries voluntarily initiated proceedings (the "Chapter 11 Cases") under chapter 11 of title 11 ("Chapter 11") of the United States Code (the "Bankruptcy Code"), to modify its capital structure, including restructuring portions of its debt, and resolve potential legal liabilities, including but not limited to those described in Note 11 as Opioid-Related Matters and Acthar Gel-Related Matters . In connection with the filing of the Chapter 11 Cases, the Company entered into a Restructuring Support Agreement (as amended, supplemented or otherwise modified, the "RSA") (further detail for which is provided in Note 2) as part of a prearranged plan of reorganization. See Note 2 for further information on the voluntary petitions for reorganization and the RSA. Substantial doubt about the Company's ability to continue as a going concern exists in light of its Chapter 11 Cases. The Company's ability to continue as a going concern is contingent upon, among other things, its ability to, subject to the approval by the U.S. Bankruptcy Court for the District of Delaware (the "Bankruptcy Court"), implement a plan of reorganization, emerge from the Chapter 11 proceedings and generate sufficient liquidity following the reorganization to meet its obligations, most notably its opioid and Acthar ® Gel (repository corticotropin injection) ("Acthar Gel")-related settlements, restructured debt obligations, and operating needs. Although management believes that the reorganization of the Company through the Chapter 11 proceedings will appropriately position the Company upon emergence, the commencement of these proceedings constituted an event of default under certain of the Company’s debt agreements, enforcement of any remedies in respect of which is automatically stayed as a result of the Chapter 11 proceedings. There are a number of risks and uncertainties associated with the Company’s bankruptcy, including, among others that: (a) the Company’s prearranged plan of reorganization may never be confirmed or become effective, (b) the RSA may be terminated by one or more of the parties thereto, (c) the Bankruptcy Court may grant or deny motions in a manner that is adverse to the Company and its subsidiaries, and (d) the Chapter 11 Cases may be converted into cases under chapter 7 of the Bankruptcy Code. The transactions contemplated by the RSA are subject to approval by the Bankruptcy Court, among other conditions. Accordingly, no assurance can be given that the transactions described therein will be consummated. As a result, the Company has concluded that management’s plans at this stage do not alleviate substantial doubt about the Company’s ability to continue as a going concern. The unaudited condensed consolidated financial statements do not include any adjustments related to the recoverability and classification of recorded asset amounts and classification of liabilities that might result from the outcome of this uncertainty. Pursuant to sections 1107(a) and 1108 of the Bankruptcy Code, the Debtors (as defined in Note 2) retain control of their assets and are authorized to operate their business as debtors-in-possession while being subject to the jurisdiction of the Bankruptcy Court. While operating as debtors-in-possession under Chapter 11, the Debtors may sell or otherwise dispose of or liquidate assets or settle liabilities, subject to the approval of the Bankruptcy Court or as otherwise permitted in the ordinary course of business and subject to applicable orders of the Bankruptcy Court, for amounts other than those reflected in the accompanying unaudited condensed consolidated financial statements. Any such actions occurring during the Chapter 11 Cases authorized by the Bankruptcy Court could materially impact the amounts and classifications of assets and liabilities reported in the Company's unaudited condensed consolidated financial statements. For more information regarding the Chapter 11 Cases, see Note 2. Fiscal Year

Reorganizations

Reorganizations	3 Months Ended
Reorganizations	Mar. 26, 2021
Reorganizations [Abstract]
Reorganization under Chapter 11 of US Bankruptcy Code Disclosure	2. Bankruptcy Proceedings Voluntary Filing Under Chapter 11 On October 12, 2020 (the "Petition Date"), Mallinckrodt plc and certain of its subsidiaries voluntarily initiated the Chapter 11 Cases under the Bankruptcy Code in the Bankruptcy Court to effectuate settlements contemplated in the RSA. The entities that filed the Chapter 11 Cases include the Company, substantially all of the Company’s U.S. subsidiaries, including certain subsidiaries of Mallinckrodt plc operating the Specialty Generics business (the "Specialty Generics Subsidiaries") and the Specialty Brands business (the "Specialty Brands Subsidiaries"), and certain of the Company’s international subsidiaries (together with the Company, Specialty Generics Subsidiaries and Specialty Brands Subsidiaries, the "Debtors"). Pursuant to orders granted by the Ontario Superior Court of Justice, the Chapter 11 proceedings commenced by a limited subset of the Company's subsidiaries have also been recognized and given effect in Canada. The Chapter 11 Cases are being jointly administered under the caption In re Mallinckrodt plc, Case No. 20-12522 (JTD). Information about the Chapter 11 Cases, including the case docket, may be found free of charge at https://restructuring.primeclerk.com/Mallinckrodt/. The Debtors continue to operate their businesses as debtors-in-possession under the jurisdiction of the Bankruptcy Court and in accordance with the applicable provisions of the Bankruptcy Code and orders of the Bankruptcy Court. As debtors-in-possession, the Debtors are authorized to continue to operate as ongoing businesses, and may pay all debts and honor all obligations arising in the ordinary course of their businesses after the Petition Date. However, the Debtors may not pay third-party claims or creditors on account of obligations arising before the Petition Date or engage in transactions outside the ordinary course of business without approval of the Bankruptcy Court. Under the Bankruptcy Code, third-party actions to collect pre-petition indebtedness owed by the Debtors, as well as most litigation pending against the Company as of the Petition Date, are subject to an automatic stay. However, under the Bankruptcy Code, certain regulatory or criminal proceedings generally are not subject to the automatic stay and may continue unless otherwise ordered by the Bankruptcy Court. Absent an order of the Bankruptcy Court providing otherwise, substantially all pre-petition liabilities will be resolved under a Chapter 11 plan of reorganization. Among other requirements, a Chapter 11 plan of reorganization must comply with the priority scheme established by the Bankruptcy Code, under which certain post-petition and secured or “priority” pre-petition liabilities need to be satisfied before general unsecured creditors and holders of the Company's equity are entitled to receive any distribution. Upon solicitation of the plan of reorganization to creditors, with an accompanying court-approved disclosure statement, certain impaired creditors and interest holders will vote by ballot to approve or reject the plan. No assurance can be given as to what values, if any, will be ascribed in the Chapter 11 Cases to the claims and interests of each of these constituencies. See Restructuring Support Agreement section below for contemplated distributions to creditors and interest holders. Under the Bankruptcy Code, the Debtors may assume, modify, assign or reject certain executory contracts and unexpired leases, including, without limitation, leases of real property and equipment, subject to the approval of the Bankruptcy Court and to certain other conditions. Generally, the rejection of an executory contract or unexpired lease is treated as a pre-petition breach of such executory contract or unexpired lease and, subject to certain exceptions, relieves the Debtors from performing their future obligations under such executory contract or unexpired lease but entitles the contract counterparty or lessor to a pre-petition general unsecured claim for damages caused by such deemed breach. Generally, the assumption of an executory contract or unexpired lease requires the Debtors to cure existing monetary defaults under such executory contract or unexpired lease and provide adequate assurance of future performance. Accordingly, any description of an executory contract or unexpired lease in this Quarterly Report on Form 10-Q, including, where applicable, the express termination rights thereunder or a quantification of their obligations, must be read in conjunction with, and is qualified by, any overriding rejection rights the Debtors have under the Bankruptcy Code. As discussed further below, the Debtors obtained approval from the Bankruptcy Court for certain "first day" motions, including motions to obtain customary relief intended to continue ordinary course operations after the Petition Date. Significant Bankruptcy Court Actions First Day Motions On October 14, 2020, the Debtors received Bankruptcy Court approval of their customary motions filed on the Petition Date ("First Day Motions") on an interim basis seeking court authorization to continue to support its business operations during the Chapter 11 Cases, including the continued payment of employee wages and benefits without interruption, payment of critical and foreign vendors, continuation of customer programs, continuation of use of existing cash management programs and allowance of certain financing payments under a cash collateral order. The First Day Motions were subsequently approved by the Bankruptcy Court on a final basis at hearings. Chapter 11 Financing In accordance with the terms of the RSA, the Company obtained the entry in the Chapter 11 Cases of an order of the Bankruptcy Court (in a form agreed with, among others, the agent under the senior secured credit facilities, lenders under the senior secured revolving credit facility and the senior secured term loans and holders of the first lien senior notes and the second lien senior notes) permitting the use of cash collateral to finance the Chapter 11 Cases. Such use is subject to an approved budget, updated and submitted every four weeks, consisting of rolling thirteen week periods subject to the consent of the lenders under the senior secured revolving credit facility and the senior secured term loans. Such order requires that the Company make cash adequate protection payments on the senior secured revolving credit facility and the senior secured term loans for, among other things, unpaid pre-petition and post-petition fees, unpaid pre-petition interest (at the specified contract rate) and post-petition interest (at a rate equal to (1) the adjusted London Inter-Bank Offered Rate ("LIBOR"), plus (2) the contract-specified applicable margin, and plus (3) an incremental 200 basis points), quarterly amortization payments on the senior secured term loans and reimbursement of certain costs. Such order further requires that we make cash adequate protection payments on the first lien senior notes and the second lien senior notes for, among other thing, unpaid pre-petition and post-petition interest (at the specified non-default interest rate) and reimbursement of certain costs. On April 13, 2021, the Debtors received Bankruptcy Court approval of their motion to amend the final cash collateral order as of March 22, 2021 to pay post-petition interest on the senior secured term loans at a rate equal to (1) the adjusted LIBOR, plus (2) the contract-specified applicable margin, and plus (3) an incremental 250 basis points for its senior secured term loans. The cash collateral order provides that it is without prejudice to (i) the rights of certain parties to request additional or alternative adequate protection from the Bankruptcy Court, (ii) the rights of lenders under the senior secured revolving credit facility and the senior secured term loans to seek a higher rate of interest and (iii) the rights of the holders of the first lien senior notes and the second lien senior notes to seek payment of a make-whole premium. With respect to the incremental 200 and 250 basis points paid on the senior secured revolving credit facility and the senior secured term loans, respectively, noted above, the Company incurred $14.5 million and $11.7 million of expense, of which $13.8 million and $7.8 million was paid, during the three months ended March 26, 2021 and fiscal 2020, respectively, which has been classified as interest expense in the unaudited condensed consolidated statement of operations. Bar Date On December 31, 2020, the Bankruptcy Court entered an order approving a deadline of February 16, 2021 at 5:00 pm (Eastern Time) (the "General Bar Date") and April 12, 2021, at 5:00 p.m. (Eastern Time) (the “Governmental Bar Date”) (collectively, together the "Bar Dates") for filing claims against the Debtors relating to the period prior to the Petition Date for general claims and government claims, respectively. The preceding Bar Dates do not cover opioid claims (inclusive of voluntary injunction opioid claims). The Company's review of asserted claims is discussed further below in Chapter 11 Claims Process . Injunctive Litigation Relief The Bankruptcy Court entered orders approving a 270-day injunction against certain opioid and Acthar Gel-related litigation matters proceeding against the Debtors and also against certain covered non-Debtors on November 25, 2020 and December 4, 2020. Refer to Note 11 for further discussion. Restructuring Support Agreement On October 11, 2020, the Company and the other Debtors entered into a RSA with creditors holding approximately 84%, by aggregate principal amount, of the Company’s outstanding guaranteed unsecured senior notes and with a group of governmental plaintiffs in the opioid litigation pending against the Company and certain of its subsidiaries, including 50 state and territory attorneys general and the court-appointed plaintiffs’ executive committee in the opioid multidistrict litigation (collectively, the "Supporting Parties"). After the bankruptcy filing, the Multi-State Governmental Entities Group entered into a joinder to the RSA that gained the support of approximately 1,300 cities, municipalities, hospital and school districts, amongst others. On March 11, 2021, an ad hoc group of lenders holding approximately $1,300.0 million, by aggregate principal amount, of the Company’s outstanding senior secured term loan due September 2024 (the "2017 Term Loan") and senior secured term loan due February 2025 (the "2018 Term Loan") have agreed to join the RSA as supporting parties and certain of the existing supporting parties have agreed to certain amendments thereto (the "Joinder and Amendment"). On April 20, 2021, the Debtors filed a joint plan of reorganization of the Debtors (the "Filed Plan") reflecting the terms of the RSA, as amended by the Joinder and Amendment. The RSA (as supplemented by the above-described joinders, including the Joinder and Amendment) incorporates the terms agreed to by the parties reflected in the term sheets attached to the RSA and such joinders, including the Joinder and Amendment, including an agreement by the Supporting Parties to support the following as memorialized in the Filed Plan, which may be amended, modified or supplemented from time to time: • A proposed resolution of all opioid-related claims against the Company and its subsidiaries . Under the terms of the amended proposed settlement (the "Amended Proposed Opioid-Related Litigation Settlement"), which would become effective upon Mallinckrodt’s emergence from the Chapter 11 process, subject to court approval and other conditions: ◦ Opioid claims would be channeled to one or more trusts, which would receive $1,600.0 million in structured payments consisting of (i) a $450.0 million payment upon the Company’s emergence from Chapter 11; (ii) a $200.0 million payment upon each of the first and second anniversaries of emergence; and (iii) a $150.0 million payment upon each of the third through seventh anniversaries of emergence with a one-year prepayment option at a discount for all but the first payment. ◦ Opioid claimants would also receive warrants for approximately 19.99% of the reorganized Company’s new outstanding shares, after giving effect to the exercise of the warrants, but subject to dilution from equity reserved under the management incentive plan, exercisable at any time on or prior to the seventh anniversary of the Company's emergence, at a strike price reflecting an aggregate equity value for the reorganized Debtors of $1,551.0 million (the "New Opioid Warrants"). ◦ Upon commencing the Chapter 11 filing, the Company will comply with an agreed-upon operating injunction with respect to the operation of its opioid business. • A proposed resolution with the U.S. Department of Justice and other governmental parties to settle a range of litigation matters and disputes relating to Acthar Gel . ◦ The Company has reached an agreement in principle with the U.S. Department of Justice ("DOJ") and other governmental parties to settle a range of litigation matters and disputes relating to Acthar Gel (the "Proposed Acthar Gel-Related Settlement") including the Medicaid lawsuit with the Centers for Medicare and Medicaid Services ("CMS"), a related False Claims Act ("FCA") lawsuit in Boston, and an Eastern District of Pennsylvania ("EDPA") FCA lawsuit relating to Acthar Gel's previous owner's (Questcor Pharmaceuticals Inc. ("Questcor")) interactions with an independent charitable foundation. Under the Proposed Acthar Gel-Related Settlement, which was conditioned upon the Company entering the Chapter 11 restructuring process, the Company has agreed to pay $260.0 million to the DOJ and other parties over seven years and reset Acthar Gel’s Medicaid rebate calculation as of July 1, 2020, such that state Medicaid programs will receive 100% rebates on Acthar Gel Medicaid sales, based on current Acthar Gel pricing. Additionally, upon execution of the settlement, the Company will dismiss its appeal of the U.S. District Court of Columbia's ("D.C. District Court") adverse decision in the Medicaid lawsuit, which appeal was filed in the U.S. Court of Appeals for the District of Columbia ("D.C. Circuit"). In turn, the U.S. Government will drop its demand for approximately $640 million in retrospective Medicaid rebates for Acthar Gel and agree to dismiss the FCA lawsuit in Boston and the EDPA FCA lawsuit. Mallinckrodt has entered into the Proposed Acthar Gel-Related Settlement to settle with the DOJ and other governmental parties solely to move past these litigation matters and disputes and will make no admission of liability. The Company is working to complete the settlement with the DOJ, as well as various states that are party to the Boston FCA litigation, over the next several months, subject to court approval. • A modification of the Company's senior secured term loans . At the end of the court-supervised process, lenders holding allowed claims in respect of the Company’s 2017 and 2018 Term Loans are expected to receive either (1) new senior secured term loans in an amount equal to the remaining principal amount of claims (as reduced by, inter alia, the excess cash flow ("ECF") Payment) bearing interest at a rate per annum equal to LIBOR plus 5.25% (with respect to the 2017 Term Loan) or LIBOR plus 5.50% (with respect to the 2018 Term Loan) (the "Adjusted Interest Rate"), maturing on the earlier of September 30, 2027 and 5.75 years after emergence and without any financial maintenance covenant or (2) payment in full in cash. A mandatory prepayment in an amount equal to $114.0 million arising from excess cash flow with respect to fiscal 2020 was paid to the holders of the Company’s 2017 and 2018 Term Loans on March 19, 2021. • The reinstatement or repayment of the Company's senior secured revolving credit facility . At the end of the court-supervised process, all allowed claims under such facility would be reinstated at existing rates and maturities. • The reinstatement of the agreements associated with the Company's 10.00% first and second lien senior notes . At the end of the court-supervised process, all allowed claims under these agreements would either be reinstated at existing rates and maturities if the applicable holders' purported make-whole claims are disallowed or, if such reinstatement is not permitted or if the applicable holders' make-whole claims are allowed, receive take-back notes at market rates with an extended maturity. • A restructuring of the Company’s unsecured notes under the guaranteed unsecured notes indentures. At the end of the court-supervised process, holders of allowed claims under indentures governing the Guaranteed Unsecured Notes (the 5.75% Senior Notes due 2022, the 5.625% Senior Notes due 2023 and the 5.50% Senior Notes due 2025) and the Guaranteed Unsecured Notes are expected to receive their pro rata share of $375.0 million of new 10.00% second lien senior secured notes due seven years after emergence and 100% of the new Mallinckrodt ordinary shares, subject to dilution by the warrants described above and certain other equity. • A proposed resolution of other remaining claims and treatment of equity holders. At the end of the court-supervised process, trade creditors and holders of allowed general unsecured claims, including holders of the 9.50% debentures due May 2022, the 8.00% debentures due March 2023 and the 4.75% senior notes due April 2023, are expected to share in $150.0 million in cash, and equity holders would receive no recovery. The restructuring transactions contemplated by the RSA will be effectuated through the Chapter 11 plan of reorganization, which among other things as outlined above, provides for a financial restructuring that would reduce the Company’s total debt by approximately $1,300.0 million. Pursuant to the RSA, each of the Debtors and the Supporting Parties has made certain customary commitments to each other in connection with the pursuit of the transactions contemplated by the term sheets attached thereto. The Debtors have agreed, among other things, to use commercially reasonable efforts to make all requisite filings with the Bankruptcy Court; continue to involve and update the Supporting Parties’ representatives in the bankruptcy process; and satisfy certain other covenants. The Supporting Parties have committed to support and vote for the Chapter 11 plan of reorganization implementing the terms of the RSA and have agreed to use commercially reasonable efforts to take, or refrain from taking, certain actions in furtherance of such support. The RSA contains milestones for the progress of the Chapter 11 Cases (the "Milestones"), which include the dates by which the Debtors are required to, among other things, obtain certain orders of the Bankruptcy Court and consummate the Debtors’ emergence from bankruptcy. Among other milestones, the RSA (as amended, including by the Joinder and Amendment) requires the Debtors to have filed a Chapter 11 plan of reorganization by no later than April 20, 2021, the Bankruptcy Court to have entered an order confirming the Chapter 11 plan of reorganization by no later than August 15, 2021 and the Debtors to have emerged from bankruptcy by no later than November 15, 2021. Each of the parties to the RSA may terminate the agreement (and thereby their support for the associated plan of reorganization) under certain limited circumstances. Any Debtor may terminate the RSA upon, among other circumstances: (i) its board of directors, after consultation with legal counsel, reasonably determining in good faith that performance under the RSA would be inconsistent with its fiduciary duties; and (ii) certain actions by the Bankruptcy Court, including dismissing the Chapter 11 Cases or converting the Chapter 11 Cases into cases under Chapter 7 of the Bankruptcy Code. The Supporting Parties also have specified termination rights, including, among other circumstances, termination rights that arise if certain of the Milestones have not been achieved, extended, or waived. Termination by one of these creditor groups will result in the termination of the RSA as to the terminating group only, with the RSA remaining in effect with respect to the Debtors and the non-terminating group. The transactions contemplated by the RSA are subject to approval by the Bankruptcy Court, among other conditions. Accordingly, no assurance can be given that the transactions described therein will be consummated. As of March 26, 2021, the outstanding borrowings under the senior secured revolving credit facility, the first lien senior notes and the second lien senior notes were classified outside of liabilities subject to compromise ("LSTC") as the related debt instruments were expected to be reinstated upon emergence from bankruptcy in accordance with the RSA. Event of default The commencement of the Chapter 11 Cases above constituted an event of default under certain of the Company’s debt agreements. Subject to any applicable provisions of the Bankruptcy Code, the Company’s debt instruments and agreements, as further described in Note 9 and within the notes to the financial statements included within the Company’s Annual Report filed on Form 10-K for the fiscal year ended December 25, 2020, provide that, as a result of the commencement of the Chapter 11 Cases, the principal amount, together with accrued and unpaid interest thereon, and in the case of the indebtedness outstanding under the senior notes, premium, if any, thereon, shall be immediately due and payable. Accordingly, all long-term debt was classified as current on the unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020. However, any efforts to enforce payment obligations under the debt instruments are automatically stayed as a result of the Chapter 11 Cases and the creditors’ rights in respect of the debt instruments are subject to the applicable provisions of the Bankruptcy Code. Financial Reporting in Reorganization Effective on the Petition Date, the Company began to apply Financial Accounting Standards Board Accounting Standards Codification ("ASC") Topic 852 - Reorganizations, which specifies the accounting and financial reporting requirements for entities reorganizing through Chapter 11 bankruptcy proceedings. These requirements include distinguishing transactions directly associated with the reorganization from activities related to the ongoing operations of the business within the financial statements for periods subsequent to the Petition Date. Expenses, realized gains and losses, and provisions for losses that are directly associated with reorganization proceedings must be reported separately as reorganization items, net in the unaudited condensed consolidated statements of operations. In addition, the unaudited condensed consolidated balance sheet must distinguish pre-petition LSTC of the Debtors from pre-petition liabilities that are not subject to compromise, post-petition liabilities, and liabilities of the subsidiaries of the Company that are not debtors in the Chapter 11 Cases. LSTC are pre-petition obligations that are not fully secured and have at least a possibility of not being repaid at the full claim amount. Where there is uncertainty about whether a secured claim will be paid or impaired pursuant to the Chapter 11 Cases, the Debtors have classified the entire amount of the claim as LSTC. Furthermore, the realization of assets and the satisfaction of liabilities are subject to uncertainty. While operating as debtors-in-possession, actions to enforce or otherwise effect the payment of certain claims against the Debtors in existence before the Petition Date are stayed while the Debtors continue business operations as debtors-in-possession. These claims are reflected as LSTC in the unaudited condensed consolidated balance sheets at March 26, 2021 and December 25, 2020. Additional claims (which could be LSTC) may arise after the Petition Date resulting from the rejection of executory contracts, including leases, and from the determination by the Bankruptcy Court (or agreement by parties-in-interest) of allowed claims for contingencies and other disputed amounts. Certain subsidiary entities are not debtors under the Chapter 11 Cases. However, condensed combined financial statements of the Debtors are not presented in the notes to the unaudited condensed consolidated financial statements as the assets and liabilities, operating results and cash flows of the non-debtor entities included in the consolidated financial statements are insignificant and, therefore, the unaudited condensed consolidated financial statements presented herein materially represent the unaudited condensed combined financial statements of the debtor entities for all periods presented. Non-debtor entity intercompany balances from/due to the debtor entities at the end of each period were: March 26, December 25, Intercompany receivables $ 135.4 $ 282.3 Intercompany payables 129.5 120.3 The intercompany balances were primarily attributable to the Company's centralized approach to cash management and financing of its operations. The permission to continue the use of existing cash management systems during the pendency of the Chapter 11 Cases was approved by the Bankruptcy Court on a final basis as part of the First Day motions as described further above. The Company is currently assessing whether or not it qualifies for fresh start accounting upon emergence from Chapter 11. If the Company were to meet the requirements to adopt the fresh start accounting rules, its assets and liabilities would be recorded at fair value as of the fresh start reporting date, which may differ materially from the recorded values of assets and liabilities on its unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020. Liabilities Subject to Compromise As a result of the commencement of the Chapter 11 Cases, the payment of pre-petition liabilities is subject to compromise or other treatment pursuant to a plan of reorganization. Generally, actions to enforce or otherwise effect payment of pre-petition liabilities are stayed. Although payment of pre-petition claims generally is not permitted, the Bankruptcy Court granted the Debtors the authority to pay certain pre-petition claims in designated categories and subject to certain terms and conditions. This relief generally was designed to preserve the value of the Debtors' business and assets. As described above, among other things, the Bankruptcy Court authorized, but did not require, the Debtors to pay certain pre-petition claims relating to employee wages and benefits, critical and foreign vendors and customer programs. The determination of how liabilities will ultimately be settled or treated cannot be made until the Bankruptcy Court confirms a Chapter 11 plan of reorganization and such plan becomes effective. Accordingly, the ultimate amount of such liabilities is not determinable at this time. GAAP requires pre-petition liabilities that are subject to compromise to be reported at the amounts expected to be allowed by the Bankruptcy Court, even if they may be settled for different amounts. The amounts currently classified as LSTC are preliminary and may be subject to future adjustments depending on Bankruptcy Court actions, further developments with respect to disputed claims, determinations of the secured status of certain claims, the values of any collateral securing such claims, rejection of executory contracts, continued reconciliation or other events. Liabilities subject to compromise at the end of each period consisted of the following: March 26, December 25, Accounts payable (1) $ 52.9 $ 61.9 Accrued interest 35.2 35.2 Debt (2) 3,446.5 1,660.7 Medicaid lawsuit 638.9 638.9 Opioid-related litigation settlement liability 1,600.0 1,600.0 Other current and non-current liabilities (3) 108.1 163.5 Pension and postretirement benefits 32.6 32.4 Total liabilities subject to compromise $ 5,914.2 $ 4,192.6 (1) Pre-petition accounts payable balances have been repaid under effectuated trade agreements pursuant to the critical vendor motion approved by the Bankruptcy Court. (2) In accordance with the Joinder and Amendment to the RSA, $1,785.8 million of outstanding senior secured term loans have been reclassified to LSTC in the Company's unaudited condensed consolidated balance sheets as of March 26, 2021. (3) The decrease in other current and non-current liabilities was primarily attributable to the Bankruptcy Court's approval of the Company's rejection of its Bedminster facility lease, which resulted in a $34.8 million adjustment to the carrying value of the respective lease liability in LSTC to reflect the estimated allowed claim amount. The remaining decrease was primarily attributable to a decrease of $15.6 million in the fair value of contingent consideration related to an asset for which the Company is no longer pursuing further development. Refer to Note 12 for further information on the valuation of contingent consideration. Contractual interest While the Chapter 11 Cases are pending, the Company is not accruing interest on its unsecured debt instruments as of the Petition Date on a go-forward basis as the Debtors do not anticipate making interest payments due under their respective unsecured debt instruments; however, the Debtors expect to pay all interest payments in full as they come due under their respective senior secured debt instruments. The total aggregate amount of interest paid pursuant to the Company's unsecured debt instruments was zero and $17.7 million during the three months ended March 26, 2021 and March 27, 2020, respectively. The total aggregate amount of interest payments due under the Company's unsecured debt instruments for the three months ended March 26, 2021 which it did not pay is $17.7 million. Chapter 11 Claims Process The Debtors have received over 49,000 proofs of claim since the Petition Date. The Debtors continue their review and analysis of certain claims including litigation claims, trade creditor claims, non-qualified benefit plan claims, customer deposits and advances, along with other tax and regulatory claims, and therefore, the ultimate liability of the Debtors for such claims may differ from the amount recorded in LSTC. To the extent that the Debtors believe that such claims will be allowed by the Bankruptcy Court, the Debtors will continue to record the expected allowed amounts of such claims as LSTC. The determination of the expected allowed amount of a claim is based on many factors, including whether the Debtors are party to a settlement agreement with applicable claimholders or their representatives, and is not necessarily limited to information available to the Debtors. Claims covered by a settlement agreement include the Proposed Acthar Gel-Related Settlement and Amended Opioid-Related Litigation Settlement (collectively, the "Proposed Settlements"). See Restructuring Support Agreement section within this note for more information on settlement of these claims. As the Debtors continue to resolve claims, differences between those final allowed claims and the liabilities recorded in the unaudited condensed consolidated balance sheet will be recognized as reorganization items, net in the Company's consolidated statements of operations in the period in which they are resolved. The determination of how liabilities will ultimately be resolved cannot be made until the Bankruptcy Court approves a plan of reorganization or approves orders related to settlement of specific liabilities. Accordingly, the ultimate amount or resolution of such liabilities is not determinable at this time. The resolution of such claims could result in substantial adjustments to the Company's consolidated financial statements. Reorganization items, net Reorganization items, net, represent amounts incurred after the Petition Date as a direct result of the Chapter 11 Cases and are comprised of bankruptcy-related professional fees and adjustments to reflect the carrying value of LSTC at their estimated allowed claim amounts, as such adjustments are approved by the Bankruptcy Court. Cash paid for reorganization items, net for the three months ended March 26, 2021 was $33.7 million. Reorganization items, net, for the three months ended March 26, 2021 included the following: March 26, Professional fees $ 77.7 Debt valuation adjustments 16.3 Adjustments of other claims (0.5) Total reorganization items, net $ 93.5

Revenue from Contracts with Cus

Revenue from Contracts with Customers Revenue from Contracts with Customers (Notes)	3 Months Ended
	Mar. 26, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	3. Revenue from Contracts with Customers Product Sales Revenue See Note 13 for presentation of the Company's net sales by product family. Reserves for variable consideration The following table reflects activity in the Company's sales reserve accounts: Rebates and Chargebacks Product Returns Other Sales Deductions Total Balance as of December 27, 2019 $ 295.8 $ 28.4 $ 13.2 $ 337.4 Provisions 457.8 3.8 13.7 475.3 Payments or credits (498.8) (6.1) (15.9) (520.8) Balance as of March 27, 2020 $ 254.8 $ 26.1 $ 11.0 $ 291.9 Balance as of December 25, 2020 $ 196.5 $ 26.6 $ 12.3 $ 235.4 Provisions (1) 488.0 25.7 13.0 526.7 Payments or credits (442.9) (10.0) (14.9) (467.8) Balance as of March 26, 2021 $ 241.6 $ 42.3 $ 10.4 $ 294.3 (1) Provisions for returns increased by $21.9 million driven by the Specialty Brands segment primarily related to a discrete return of product sold during the three months ended March 26, 2021. Product sales transferred to customers at a point in time and over time were as follows: Three Months Ended March 26, March 27, Product sales transferred at a point in time 75.7 % 78.5 % Product sales transferred over time 24.3 21.5 Transaction price allocated to the remaining performance obligations The following table includes estimated revenue from contracts extending greater than one year for certain of the Company's hospital products that are expected to be recognized in the future related to performance obligations that were unsatisfied or partially unsatisfied as of March 26, 2021: Remainder of Fiscal 2021 $ 70.9 Fiscal 2022 41.0 Fiscal 2023 9.9 Thereafter 0.3 Costs to fulfill a contract As of March 26, 2021 and December 25, 2020, the total net book value of the devices used in the Company's portfolio of drug-device combination products, which are used in satisfying future performance obligations, were $27.0 million and $25.8 million, respectively, and were classified in property, plant and equipment, net, on the unaudited condensed consolidated balance sheets. The associated depreciation expense recognized during the three months ended March 26, 2021 and March 27, 2020 was $1.4 million and $1.5 million, respectively. Product Royalty Revenues The Company licenses certain rights to Amitiza ® (lubiprostone) ("Amitiza") to a third party in exchange for royalties on net sales of the product. The royalty rates consist of several tiers ranging from 18.0% to 26.0% with the royalty rate resetting every year. Additionally, beginning in fiscal 2021, Par Pharmaceutical, Inc., et al. (collectively Par) will pay the Company a double-digit royalty based on a percentage of the gross profits of the licensed products sold during the term of the agreement. Under both agreements, the Company recognizes such royalty revenue as the related sales occur. The associated royalty revenue recognized was as follows: Three Months Ended March 26, March 27, Royalty revenue $ 35.4 $ 15.6

Income Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 26, 2021
Income Tax Disclosure [Abstract]
Income Tax Disclosure	4. Income Taxes As further discussed in Note 1, the Company concluded that there is substantial doubt about its ability to continue as a going concern within one year from the date of issuance of the unaudited condensed consolidated financial statements. The Company considered this in determining that certain net deferred tax assets were no longer more likely than not realizable. As a result, as of March 26, 2021, all of the Company's net deferred tax assets in applicable tax jurisdictions are fully offset by a valuation allowance. The Company recognized an income tax benefit of $16.4 million on a loss from continuing operations before income taxes of $160.6 million for the three months ended March 26, 2021, and an income tax benefit of $18.9 million on a loss from continuing operations before income taxes of $75.6 million for the three months ended March 27, 2020. This resulted in effective tax rates of 10.2% and 25.0% for the three months ended March 26, 2021 and March 27, 2020, respectively. The income tax benefit for the three months ended March 26, 2021 was comprised of $13.0 million of current tax benefit and $3.4 million of deferred tax benefit. The current tax benefit was predominantly related to an increase to prepaid taxes, partially offset by changes to uncertain tax positions. The deferred tax benefit was predominantly related to intangible asset amortization, partially offset by utilization of loss carryforwards in non-valuation allowance jurisdictions. The income tax benefit for the three months ended March 27, 2020 was comprised of $22.4 million of current tax benefit and $3.5 million of deferred tax expense. The deferred tax expense was predominantly comprised of deferred tax expense as a result of the Coronavirus Aid, Relief, and Economic Security ("CARES") Act partially offset by deferred tax benefit related to previously acquired intangibles. The income tax benefit was $16.4 million for the three months ended March 26, 2021, compared with an income tax benefit of $18.9 million for the three months ended March 27, 2020. The $2.5 million net decrease in the tax benefit included a decrease of $11.0 million attributed to the CARES Act and a decrease of $8.0 million attributed to uncertain tax positions, partially offset by an increase of $15.4 million attributed to changes in the timing, amount and jurisdictional mix of income and an increase of $1.1 million attributed to separation costs, reorganization items, net and restructuring charges, net. During the three months ended March 26, 2021, and fiscal 2020, the net cash payments for income taxes were $8.1 million and $39.9 million, respectively. The Company's unrecognized tax benefits, excluding interest, totaled $356.2 million and $349.0 million as of March 26, 2021 and December 25, 2020, respectively. The net increase of $7.2 million primarily resulted from a net increase of prior period tax positions. If favorably settled, $80.9 million of unrecognized tax benefits as of March 26, 2021 would benefit the effective tax rate. The total amount of accrued interest and penalties related to these obligations was $19.8 million and $16.7 million as of March 26, 2021 and December 25, 2020, respectively. It is reasonably possible that within the next twelve months the unrecognized tax benefits could decrease by up to $41.7 million and the amount of related interest and penalties could decrease by up to $9.8 million as a result of payments or releases due to the resolution of examinations, appeals and litigation and the expiration of various statutes of limitation.

Earnings per Share

Earnings per Share	3 Months Ended
Earnings per Share	Mar. 26, 2021
Earnings Per Share [Abstract]
Earnings per Share	5. Loss per Share Loss per share is computed by dividing net loss by the number of weighted-average shares outstanding during the period. Dilutive securities, including participating securities, have not been included in the computation of loss per share as the Company reported a net loss from continuing operations during all periods presented below and therefore, the impact would be anti-dilutive. The weighted-average number of shares outstanding used in the computations of both basic and diluted loss per share were as follows ( in millions ): Three Months Ended March 26, March 27, Basic 84.6 84.2

Inventories

Inventories	3 Months Ended
Inventories	Mar. 26, 2021
Inventory, Net [Abstract]
Inventories	6. Inventories Inventories were comprised of the following at the end of each period: March 26, December 25, Raw materials and supplies $ 58.0 $ 58.1 Work in process 205.9 200.7 Finished goods 99.5 86.1 $ 363.4 $ 344.9

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
Property, Plant and Equipment	Mar. 26, 2021
Property, Plant and Equipment
Property, Plant and Equipment Disclosure	7. Property, Plant and Equipment The gross carrying amount and accumulated depreciation of property, plant and equipment were comprised of the following at the end of each period: March 26, December 25, 2020 Property, plant and equipment, gross $ 1,874.2 $ 1,910.9 Less: accumulated depreciation (1,079.8) (1,077.8) Property, plant and equipment, net $ 794.4 $ 833.1 Depreciation expense was as follows: Three Months Ended March 26, March 27, Depreciation expense $ 24.3 $ 25.5

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
Goodwill and Intangible Assets	Mar. 26, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	8. Intangible Assets The gross carrying amount and accumulated amortization of intangible assets were comprised of the following at the end of each period: March 26, 2021 December 25, 2020 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortizable: Completed technology $ 10,394.6 $ 4,730.0 $ 10,394.6 $ 4,586.6 License agreements 120.1 79.1 120.1 78.1 Trademarks 77.7 24.4 77.7 23.5 Total $ 10,592.4 $ 4,833.5 $ 10,592.4 $ 4,688.2 Non-Amortizable: Trademarks $ 35.0 $ 35.0 In-process research and development 180.8 245.3 Total $ 215.8 $ 280.3 Terlipressin During September 2020, the U.S. Food and Drug Administration ("FDA") issued a Complete Response Letter ("CRL") regarding the Company's New Drug Application ("NDA") seeking approval for the investigational agent terlipressin to treat adults with hepatorenal syndrome type 1 ("HRS-1"). The CRL stated that, based on the available data, the agency cannot approve the terlipressin NDA in its current form and requires more information to support a positive risk-benefit profile for terlipressin for patients with HRS-1. In response to receipt of the CRL, the Company had an End of Review Meeting on October 26, 2020 and a Type A Meeting on January 29, 2021 with the FDA where both parties engaged in constructive dialogue in an effort to clarify a viable path to U.S. approval. As the Company continues to engage with the FDA over the coming months, it will continue to assess the impact of any changes to planned revenue or earnings on the fair value of the associated in-process research and development asset of $81.0 million included within intangible assets, net on the unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020. The Company annually tests the indefinite-lived intangible assets for impairment, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable by either a qualitative or income approach. Management relies on a number of qualitative factors when considering a potential impairment such as changes to planned revenue or earnings that could affect significant inputs used to determine the fair value of the indefinite-lived intangible asset. MNK-6105 and MNK-6106 During the three months ended March 26, 2021, the Company recognized a full impairment on its Specialty Brands in-process research and development ("IPR&D") asset related to MNK-6105 and MNK-6106 of $64.5 million. The Company has decided it will no longer pursue further development of this asset. Intangible asset amortization expense Intangible asset amortization expense was as follows: Three Months Ended March 26, March 27, Amortization expense $ 145.3 $ 197.6 The estimated aggregate amortization expense on intangible assets owned by the Company is expected to be as follows: Remainder of Fiscal 2021 $ 435.8 Fiscal 2022 581.1 Fiscal 2023 581.1 Fiscal 2024 581.1 Fiscal 2025 579.6

Debt

Debt	3 Months Ended
Debt	Mar. 26, 2021
Debt Disclosure [Abstract]
Debt Disclosure	9. Debt The commencement of the Chapter 11 Cases constituted an event of default under certain of the Company’s debt agreements. Accordingly, all debt not reclassified as LSTC with original long-term stated maturities was classified as current on the unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020. However, any efforts to enforce payment obligations under the Company's debt instruments are automatically stayed as a result of the Chapter 11 Cases and the creditors’ rights in respect of the debt instruments are subject to the applicable provisions of the Bankruptcy Code. See Note 2 for further information. Debt was comprised of the following at the end of each period: March 26, 2021 December 25, 2020 Principal Unamortized Discount and Debt Issuance Costs (1) Principal Unamortized Discount and Debt Issuance Costs (1) Secured debt: Term loan due September 2024 $ 1,411.2 $ — $ 1,505.2 $ 12.3 Term loan due February 2025 374.6 — 399.5 5.0 10.00% first lien senior notes due April 2025 495.0 7.3 495.0 7.7 10.00% second lien senior notes due April 2025 322.9 7.6 322.9 8.0 Revolving credit facility 900.0 1.3 900.0 1.7 Total secured debt 3,503.7 16.2 3,622.6 34.7 Unsecured debt: 9.50% debentures due May 2022 10.4 — 10.4 — 5.75% senior notes due August 2022 610.3 — 610.3 — 8.00% debentures due March 2023 4.4 — 4.4 — 4.75% senior notes due April 2023 133.7 — 133.7 — 5.625% senior notes due October 2023 514.7 — 514.7 — 5.50% senior notes due April 2025 387.2 — 387.2 — Total unsecured debt 1,660.7 — 1,660.7 — Total debt, prior to reclassification to liabilities subject to compromise 5,164.4 16.2 5,283.3 34.7 Less: Current portion (1,717.9) (16.2) (3,622.6) (34.7) Less: Amounts reclassified to liabilities subject to compromise (2) (3,446.5) — (1,660.7) — Total long-term debt, net of current portion $ — $ — $ — $ — (1) As a result of the Company's Chapter 11 Cases, the Company expensed $16.3 million of unamortized discount and debt issuance costs, net, recorded in reorganization items, net in the unaudited condensed consolidated statement of operations during the three months ended March 26, 2021. (2) In connection with the Company’s Chapter 11 Cases, $3,446.5 million and $1,660.7 million outstanding secured and unsecured debt instruments have been reclassified to LSTC in the Company's unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020, respectively. Up to the date of reclassification to LSTC, the Company continued to accrue interest expense in relation to these debt instruments reclassified to LSTC. Refer to Note 2 for further information. As of March 26, 2021, the applicable interest rate and outstanding borrowings on the Company's variable-rate debt instruments were as follows: Applicable interest rate Outstanding borrowings Term loan due September 2024 (1) 6.00 % $ 1,411.2 Term loan due February 2025 (1) 6.25 374.6 Revolving credit facility 4.47 900.0 (1) The applicable interest rate for the senior secured term loans includes the incremental 250 basis points as a result of the amendment to the cash collateral order that took effect on March 22, 2021. Refer to Note 2 for further discussion on the amendment. As of March 26, 2021, the Company was fully drawn on its $900.0 million revolving credit facility.

Guarantees

Guarantees	3 Months Ended
Guarantees	Mar. 26, 2021
Guarantees [Abstract]
Guarantees	10. Guarantees In disposing of assets or businesses, the Company has from time to time provided representations, warranties and indemnities to cover various risks and liabilities, including unknown damage to assets, environmental risks involved in the sale of real estate, liability to investigate and remediate environmental contamination at waste disposal sites and manufacturing facilities, and unidentified tax liabilities related to periods prior to disposition. The Company assesses the probability of potential liabilities related to such representations, warranties and indemnities and adjusts potential liabilities as a result of changes in facts and circumstances. The Company believes, given the information currently available, that the ultimate resolutions will not have a material adverse effect on its financial condition, results of operations and cash flows. In connection with the sale of the Specialty Chemical business (formerly known as Mallinckrodt Baker) in fiscal 2010, the Company agreed to indemnify the purchaser with respect to various matters, including certain environmental, health, safety, tax and other matters. The indemnification obligations relating to certain environmental, health and safety matters have a term of 17 years from the sale, while some of the other indemnification obligations have an indefinite term. The amount of the liability relating to all of these indemnification obligations included in other liabilities on the Company's unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020 was $15.2 million and $15.4 million, respectively, of which $12.4 million and $12.7 million, respectively, related to environmental, health and safety matters. The value of the environmental, health and safety indemnity was measured based on the probability-weighted present value of the costs expected to be incurred to address environmental, health and safety claims made under the indemnity. The aggregate fair value of these indemnification obligations did not differ significantly from their aggregate carrying value as of March 26, 2021 and December 25, 2020. As of March 26, 2021, the maximum future payments the Company could be required to make under these indemnification obligations were $70.2 million. The Company was required to pay $30.0 million into an escrow account as collateral to the purchaser, of which $19.0 million remained in restricted cash, included in other long-term assets on the unaudited condensed consolidated balance sheets as of both March 26, 2021 and December 25, 2020, respectively. The Company has recorded liabilities for known indemnification obligations included as part of environmental liabilities, which are discussed within the notes to the financial statements included within the Company's Annual Report filed on Form 10-K for the fiscal year ended December 25, 2020. The Company is also liable for product performance; however, the Company believes, given the information currently available, that the ultimate resolution of any such claims will not have a material adverse effect on its financial condition, results of operations and cash flows.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 26, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies The Company is subject to various legal proceedings and claims, including government investigations, environmental matters, product liability matters, patent infringement claims, personal injury, employment disputes, contractual disputes and other commercial disputes, including those described below. Although it is not feasible to predict the outcome of these matters, the Company believes, unless otherwise indicated below, given the information currently available, that their ultimate resolution will not have a material adverse effect on its financial condition, results of operations and cash flows. On October 12, 2020, the Company announced that Mallinckrodt plc and certain of its subsidiaries voluntarily initiated the Chapter 11 Cases under the Bankruptcy Code in the Bankruptcy Court. As a result of initiating the Chapter 11 Cases, all litigation and proceedings against the Company have been automatically stayed, subject to certain limited exceptions. In addition, the Bankruptcy Court issued orders enjoining certain litigation against the Company and various individuals named in certain of the litigation described below that might otherwise be subject to such an exception. For further information about the Chapter 11 Cases, refer to Note 2. Governmental Proceedings Opioid-Related Matters Since 2017, multiple U.S. states, counties, a territory, other governmental persons or entities and private plaintiffs have filed lawsuits against certain entities of the Company, as well as various other manufacturers, distributors, pharmacies, pharmacy benefit managers, individual doctors and/or others, asserting claims relating to defendants' alleged sales, marketing, distribution, reimbursement, prescribing, dispensing and/or other practices with respect to prescription opioid medications, including certain of the Company's products. As of May 3, 2021, the cases the Company is aware of include, but are not limited to, approximately 2,615 cases filed by counties, cities, Native American tribes and/or other government-related persons or entities; approximately 270 cases filed by hospitals, health systems, unions, health and welfare funds or other third-party payers; approximately 124 cases filed by individuals; approximately six cases filed by schools and school boards; and 17 cases filed by the Attorneys General for New Mexico, Kentucky, Rhode Island, Georgia, Florida, Alaska, New York, Nevada, South Dakota, New Hampshire, Louisiana, Illinois, Mississippi, West Virginia, Puerto Rico, Ohio, and Idaho, with Idaho being the only state Attorney General to file in federal as opposed to state court. As of May 3, 2021, the Mallinckrodt defendants in these cases consist of Mallinckrodt plc and the following subsidiaries of Mallinckrodt plc: Mallinckrodt Enterprises LLC, Mallinckrodt LLC, SpecGx LLC, Mallinckrodt Brand Pharmaceuticals Inc., Mallinckrodt Inc., MNK 2011 Inc., and Mallinckrodt Enterprises Holdings, Inc. Certain of the lawsuits have been filed as putative class actions. On October 8, 2020, the State of Rhode Island filed a lawsuit against the Company's President and Chief Executive Officer ("CEO"), Mark C. Trudeau, asserting similar claims relating to the marketing and distribution of prescription opioid medications. Rhode Island has voluntarily agreed to a stay of the lawsuit against Mr. Trudeau. Most pending federal lawsuits have been coordinated in a federal multi-district litigation (“MDL”) pending in the U.S. District Court for the Northern District of Ohio. The MDL court has issued a series of case management orders permitting motion practice addressing threshold legal issues in certain cases, allowing discovery, setting pre-trial deadlines and setting a trial date on October 21, 2019 for two cases originally filed in the Northern District of Ohio by Summit County and Cuyahoga County against opioid manufacturers, distributors, and pharmacies ("Track 1 Cases"). The counties claimed that opioid manufacturers' marketing activities changed the medical standard of care for treating both chronic and acute pain, which led to increases in the sales of their prescription opioid products. They also alleged that opioid manufacturers' and distributors' failure to maintain effective controls against diversion was a substantial cause of the opioid crisis. On September 30, 2019, the Company announced that Mallinckrodt plc, along with its wholly owned subsidiaries Mallinckrodt LLC and SpecGx LLC, had executed a definitive settlement agreement and release with Cuyahoga and Summit Counties in Ohio. The settlement fully resolves the Track 1 cases against all named Mallinckrodt entities that were scheduled to go to trial in October 2019 in the MDL. Under the agreement, the Company paid $24.0 million in cash on October 1, 2019. In addition, the Company will provide $6.0 million in generic products, including addiction treatment products, and will also provide a $0.5 million payment in two years in recognition of the counties' time and expenses. Further in the event of a comprehensive resolution of government-related opioid claims, the Company has agreed that the two plaintiff counties will receive the value they would have received under such a resolution, less the payments described above. All named Mallinckrodt entities were dismissed with prejudice from the lawsuit. The value of the settlement should not be extrapolated to any other opioid-related cases or claims. Other lawsuits remain pending in various state courts. In some jurisdictions, certain of the state lawsuits have been consolidated or coordinated for pre-trial proceedings before a single court within their respective state court systems. The lawsuits assert a variety of claims, including, but not limited to, public nuisance, negligence, civil conspiracy, fraud, violations of the Racketeer Influenced and Corrupt Organizations Act (“RICO”) or similar state laws, violations of state Controlled Substances Acts or state False Claims Acts, product liability, consumer fraud, unfair or deceptive trade practices, false advertising, insurance fraud, unjust enrichment, negligence, negligent misrepresentation, and other common law and statutory claims arising from defendants' manufacturing, distribution, marketing and promotion of opioids and seek restitution, damages, injunctive and other relief and attorneys' fees and costs. The claims generally are based on alleged misrepresentations and/or omissions in connection with the sale and marketing of prescription opioid medications and/or an alleged failure to take adequate steps to prevent diversion. Opioid-Related Litigation Settlement. On February 25, 2020, the Company announced that it had reached an agreement in principle with a court-appointed plaintiffs' executive committee representing the interest of thousands of plaintiffs in the MDL and supported by a broad-based group of 48 state and U.S. Territory Attorneys General on the terms of a global settlement that would resolve all opioid-related claims against the Company and its subsidiaries (the "Opioid-Related Litigation Settlement"). The Opioid-Related Litigation Settlement contemplated the filing of voluntary petitions under Chapter 11 by the Specialty Generics Subsidiaries and the establishment of a trust for the benefit of plaintiffs holding opioid-related claims against the Company (the "Opioid Claimant Trust"). Furthermore, under the terms of the Opioid-Related Litigation Settlement, subject to court approval and other conditions, it was contemplated that, the Company would (1) make cash payments of $1,600.0 million in structured payments over eight years, beginning upon the Specialty Generics Subsidiaries’ emergence from the completed Chapter 11 case, the substantial majority of which would be expected to be contributed to the Opioid Claimant Trust and (2) issue warrants with an eight year term to the Opioid Claimant Trust exercisable at a strike price of $3.15 per share to purchase the Company’s ordinary shares that would represent approximately 19.99% of the Company's fully diluted outstanding shares, including after giving effect to the exercise of the warrants (the “Settlement Warrants”). Amended Opioid-Related Litigation Settlement. In conjunction with the Company's Chapter 11 filing on October 12, 2020, the Company entered into a RSA which includes a proposed resolution of all opioid-related claims against the Company and its subsidiaries that supersedes the Opioid-Related Litigation Settlement, The RSA provides that, upon the Company’s emergence from the Chapter 11 process, subject to court approval and other conditions: • Opioid claims would be channeled to one or more trusts, which would receive $1,600.0 million in structured payments consisting of (i) a $450.0 million payment upon the Company’s emergence from Chapter 11; (ii) a $200.0 million payment upon each of the first and second anniversaries of emergence; and (iii) a $150.0 million payment upon each of the third through seventh anniversaries of emergence with a one-year prepayment option at a discount for all but the first payment. • Opioid claimants would also receive warrants for approximately 19.99% of the reorganized Company’s new outstanding shares, after giving effect to the exercise of the warrants, but subject to dilution from equity reserved under the management incentive plan, exercisable at any time on or prior to the seventh anniversary of the Company's emergence, at a strike price reflecting an aggregate equity value for the reorganized Debtors of $1,551.0 million (the "New Opioid Warrants"). • Upon commencing the Chapter 11 filing, the Company will comply with an agreed-upon operating injunction with respect to the operation of its opioid business. As of both March 26, 2021 and December 25, 2020, the Company maintained an accrual for this contingency of $1,600.0 million. No value has been ascribed to the warrants as of March 26, 2021 or December 25, 2020 as the Company cannot reasonably estimate the equity value upon emergence. For further information on the terms of this proposed resolution, refer to Note 2. Other Opioid-Related Matters. On June 1, 2020, a putative class action lawsuit was filed against Mallinckrodt plc, Mallinckrodt Canada ULC, Her Majesty the Queen in right of the Province of British Columbia ("Province") and the College of Pharmacists of British Columbia ("College") in the Supreme Court of British Columbia, captioned Laura Shaver v. Mallinckrodt Canada ULC, et al. , Court File No. VLC-S-S-205793. The action purports to be brought on behalf of any persons: (1) prescribed Methadose for opioid agonist treatment in British Columbia after March 1, 2014; (2) covered by Pharmacare Plan C within British Columbia who were prescribed Methadose for opioid agonist treatment after February 1, 2014; (3) who transitioned from compounded methadone to Methadose for opioid agonist treatment in British Columbia after March 1, 2014; (4) covered by Pharmacare Plan C within British Columbia who were transitioned from compounded methadone to Methadose for opioid agonist treatment after February 1, 2014; or (5) falling within such other class definition as the British Columbia Court may approve. The suit generally alleges that the Province’s decision to grant Methadose coverage under Pharmacare Plan C and remove compounded methadone from coverage under Pharmacare Plan C had adversely affected those being treated for opioid use disorder due to Methadose allegedly being a significantly less effective treatment than generic compounded methadone. The suit asserts that the Province, the College and the Mallinckrodt defendants knew (or ought to have known) about, failed to warn patients about and made false representations concerning, the efficacy of Methadose and the risks of switching from compounded methadone to Methadose. The suit seeks general, special, aggravated, punitive and exemplary damages in an unspecified amount, costs and interest and injunctive relief against the Province, the College and the Mallinckrodt defendants. Pursuant to two orders granted by the Ontario Superior Court of Justice (Commercial List) ("Canadian Court") on October 15, 2020, the Chapter 11 proceedings commenced by Mallinckrodt plc and Mallinckrodt Canada ULC pursuant to the U.S. Bankruptcy Code were recognized and given effect in Canada. Among other things, the Canadian Court has stayed all proceedings against the Mallinckrodt defendants, including the British Columbia class action proceedings. The Canadian Court granted a further order on February 25, 2021, staying the British Columbia class action proceedings against all defendants. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with this lawsuit. Acthar Gel-Related Matters Medicaid Lawsuit. In May 2019, CMS issued a final decision directing the Company to revert to the original base date AMP used to calculate Medicaid drug rebates for Acthar Gel despite CMS having given the previous owner of the product, Questcor, written authorization in 2012 to reset the base date AMP. Upon receipt of CMS’s final decision, the Company filed suit in the D.C. District Court against the Agency under the Administrative Procedure Act seeking to have the decision declared unlawful and set aside. In March 2020, the Company received an adverse decision from the D.C. District Court. The Company immediately sought reconsideration by the D.C. District Court, which was denied. The Company then appealed the D.C. District Court’s decision to the D.C. Circuit. In June 2020, while its appeal remained pending, the Company was required to revert to the original base date AMP for Acthar in the government’s price reporting system. As a result of this contingency, the Company incurred a retrospective one-time charge of $641.1 million (the "Acthar Gel Medicaid Retrospective Rebate"), of which $536.0 million and $105.1 million was reflected as a component of net sales and operating expenses, respectively, in the consolidated statement of operations for fiscal 2020. The $105.1 million reflected as a component of operating expenses represented a pre-acquisition contingency related to the portion of the Acthar Gel Medicaid Retrospective Rebate that arose from sales of Acthar Gel prior to the Company’s acquisition of Questcor in August 2014. As of March 26, 2021 and December 25, 2020, $638.9 million related to the Medicaid lawsuit was recorded within LSTC. The D.C. Circuit heard argument on the merits of the Company's appeal in September 2020, prior to the Company's filing of the Chapter 11 Cases on October 12, 2020. At the joint request of the parties, the D.C. Circuit has agreed to hold the case in abeyance pending completion of the Proposed Acthar Gel-Related Settlement, which was conditioned upon the Company entering the Chapter 11 restructuring process. Pursuant to the Proposed Acthar Gel-Related Settlement, the Company has agreed to pay $260.0 million over seven years and to reset Acthar Gel’s Medicaid rebate calculation as of July 1, 2020, such that state Medicaid programs will receive 100% rebates on Acthar Gel Medicaid sales, based on current Acthar Gel pricing. Additionally, upon execution of the Proposed Acthar Gel-Related Settlement, the Company will dismiss its D.C. Circuit appeal. The Company expects that the Proposed Acthar Gel-Related Settlement will be completed over the next several months, subject to Bankruptcy Court approval. Commercial and Securities Litigation Other Acthar Gel-Related Matters. On March 12, 2021, the plaintiffs in City of Rockford v. Mallinckrodt ARD, Inc., et al (“Rockford”), United Ass’n of Plumbers and Pipefitters Local 322 of Southern New Jersey v. Mallinckrodt ARD, LLC, et. al (“Local 322”), Steamfitters Local Union No. 420 v. Mallinckrodt ARD, LLC, et al. (“Steamfitters”), Int'l Union of Operating Engineers Local 542 v. Mallinckrodt ARD Inc., et al. (“Local 542”) and Acument Global Technologies, Inc., v. Mallinckrodt ARD Inc., et al. (“Acument”) filed a motion with the Joint Panel on Multi-District Litigation (“JPML”) under 28 U.S.C. § 1407 requesting that those cases and others alleging claims related to the price of Acthar Gel (including Health Care Service Corp. v. Mallinckrodt ARD LLC, et al. (“HCSC”), City of Marietta v. Mallinckrodt ARD LLC (“Marietta”), Humana Inc. v. Mallinckrodt ARD LLC (“Humana”) , MSP Recovery Claims, Series II, LLC, et al. v. Mallinckrodt ARD, Inc., et al. (“MSP”) and U.S. ex rel. Strunck v. Mallinckrodt ARD LLC ("Strunck") ) be transferred to the Northern District of Illinois for coordinated or consolidated pretrial proceedings as a MDL (the “Section 1407 Motion”). The Company has opposed the Section 1407 Motion. In April 2021, the U.S. District Courts in the Northern District of Illinois and the Eastern District of Pennsylvania ("EDPA") stayed consideration of the Company’s motions to transfer Rockford, MSP and Steamfitters to the District of Delaware pending a decision by the JPML. The EDPA District Court also denied Local 542 's motion for reconsideration of the court's order transferring that case to the District of Delaware. On April 30, 2021, the Company filed several pleadings in the Chapter 11 Cases in respect of Acthar Gel-based claims, including without limitation the following: (a) objections to putative class proofs of claim filed by the City of Rockford, United Association of Plumbers and Pipefitters Local 322 of Southern New Jersey, Steamfitters Local Union No. 420, and Acument Global Technologies, Inc.; (b) objections to all purportedly Acthar Gel-related proofs of claim that state no basis for Acthar Gel-related liability against the named debtor; (c) a motion for establishment of an administrative claims bar date that will require all Acthar Gel claimants, among others, to promptly file any requests for payment of purported administrative claims; and (d) an adversary proceeding seeking a declaratory judgment that the claims of the City of Rockford, as a governmental unit, are dischargeable in the Chapter 11 Cases. For additional details on Rockford, Local 322, Steamfitters, Local 542, Acument, HCSC, Marietta, Humana , MSP and Strunck refer to the notes to the financial statements included within the Company's Annual Report filed on Form 10-K for the fiscal year ended December 25, 2020. Putative Class Action Securities Litigation (Strougo) . In July 2019, a putative class action lawsuit was filed against the Company, its CEO Mark C. Trudeau, its Chief Financial Officer ("CFO") Bryan M. Reasons, its former Interim CFO George A. Kegler and its former CFO Matthew K. Harbaugh, in the U.S. District Court for the Southern District of New York, captioned Barbara Strougo v. Mallinckrodt plc, et al . The complaint purports to be brought on behalf of all persons who purchased or otherwise acquired Mallinckrodt's securities between February 28, 2018 and July 16, 2019. The lawsuit generally alleges that the defendants made false and/or misleading statements in violation of Sections 10(b) and 20(a) of the Exchange Act and Rule 10b-5 promulgated thereunder related to the Company's clinical study designed to assess the efficacy and safety of its Acthar Gel in patients with amyotrophic lateral sclerosis. The lawsuit seeks monetary damages in an unspecified amount. A lead plaintiff was designated by the court on June 25, 2020, and on July 30, 2020, the court approved the transfer of the case to the U.S. District Court for the District of New Jersey. On August 10, 2020, an amended complaint was filed by the lead plaintiff alleging an expended putative class period of May 3, 2016 through March 18, 2020 against the Company and Mark C. Trudeau, Bryan M. Reasons, George A. Kegler and Matthew K. Harbaugh, as well as newly named defendants Kathleen A. Schaefer, Angus C. Russell, Melvin D. Booth, JoAnn A. Reed, Paul R. Carter, and Mark J. Casey (collectively with Trudeau, Reasons, Kegler and Harbaugh, the "Strougo Defendants"). The amended complaint claims that the defendants made false and/or misleading statements and/or failed to disclose that: (i) the CMS had informed the Company that it was using the wrong base date AMP for calculating the Medicaid rebate the Company owed CMS for Acthar Gel each quarter since 2014; (ii) the Company’s reported net income was improperly inflated in violation of GAAP; (iii) the Company’s contingent liabilities associated with the rebates owed to CMS for Acthar Gel were misrepresented; (iv) the Company’s fiscal year 2019 guidance for Acthar Gel net sales was false; (v) the Company failed to disclose material information regarding the cases captioned Landolt v. Mallinckrodt ARD LLC, No. 1:18-cv-11931-PBS (D. Mass.) (Landolt) and U.S. ex rel. Strunck v. Mallinckrodt ARD LLC, No. 2:12-cv-0175-BMS (E.D. Pa.) (Strunck) , or the related investigation by the DOJ and (vi) the Company failed to disclose that the clinical trials for Acthar Gel were purportedly initiated in order to make it appear that alternative revenue opportunities for Acthar Gel existed and thus offset the expected 10% decline in net sales as a result of the rebates the Company now had to pay. On October 1, 2020, the defendants filed a motion to dismiss the amended complaint. The defendants intend to vigorously defend themselves in this matter. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with this lawsuit. As to the Company, this litigation is subject to the automatic stay under §362 of the Bankruptcy Code, and on December 4, 2020, the Bankruptcy Court also enjoined proceedings against the Strougo Defendants. The plaintiffs subsequently appealed the Bankruptcy Court action to the U.S. District Court in Delaware through a motion for reconsideration, which was denied by that court on January 27, 2021. Generic Price Fixing Litigation Canadian (Eaton) Litigation . In December 2020, the Company received a statement of claim filed in federal court in Toronto, Ontario, Canada, naming the Company, Mallinckrodt Canada ULC, Mallinckrodt LLC and a predecessor to MNK 2011 LLC, as well as other pharmaceutical manufacturers, as defendants in an action captioned Kathryn Eaton v Teva Canada Limited et al . The claim purports to be brought on behalf of all persons or entities in Canada who, from January 1, 2012 to the present, purchased generic drugs in the private sector. The allegations and requests for relief in the statement of claim, in substance, are similar to those in the 1199SEIU National Benefit Fund litigation, and include the claim that the Company breached the Competition Act in Canada. As a result of the Eaton action being served on the Mallinckrodt defendants, Mallinckrodt Canada ULC sought, and the Canadian Court granted, an order on April 20, 2021, among other things: (1) recognizing the Chapter 11 Cases of, and granting Canadian stays with respect to, Mallinckrodt LLC and MNK 2011 LLC; and (2) declaring that the Eaton action is stayed as against each of the Mallinckrodt defendants and the named predecessor to MNK 2011 LLC. Other Matters The Company's legal proceedings and claims are further described within the notes to the financial statements included within the Company's Annual Report filed on Form 10-K for the fiscal year ended December 25, 2020.

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	3 Months Ended
Financial Instruments and Fair Value Measurements	Mar. 26, 2021
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurements	12. Financial Instruments and Fair Value Measurements Fair value is defined as the exit price that would be received from the sale of an asset or paid to transfer a liability, using assumptions that market participants would use in pricing an asset or liability. The fair value guidance establishes a three-level fair value hierarchy, which maximizes the use of observable inputs and minimizes the use of unobservable inputs used in measuring fair value. The levels within the hierarchy are as follows: Level 1— observable inputs such as quoted prices in active markets for identical assets or liabilities; Level 2— significant other observable inputs that are observable either directly or indirectly; and Level 3— significant unobservable inputs in which there is little or no market data, which requires the Company to develop its own assumptions. The following tables provide a summary of the significant assets and liabilities that are measured at fair value on a recurring basis at the end of each period: March 26, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 32.9 $ 23.1 $ 9.8 $ — Equity securities 39.5 39.5 — — $ 72.4 $ 62.6 $ 9.8 $ — Liabilities: Deferred compensation liabilities $ 32.1 $ — $ 32.1 $ — Contingent consideration and acquired contingent liabilities 23.9 — — 23.9 $ 56.0 $ — $ 32.1 $ 23.9 December 25, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 33.0 $ 23.5 $ 9.5 $ — Equity securities 31.1 31.1 — — $ 64.1 $ 54.6 $ 9.5 $ — Liabilities: Deferred compensation liabilities $ 38.0 $ — $ 38.0 $ — Contingent consideration and acquired contingent liabilities 34.7 — — 34.7 $ 72.7 $ — $ 38.0 $ 34.7 Debt and equity securities held in rabbi trusts. Debt securities held in rabbi trusts primarily consist of U.S. government and agency securities and corporate bonds. When quoted prices are available in an active market, the investments are classified as level 1. When quoted market prices for a security are not available in an active market, they are classified as level 2. Equity securities held in rabbi trusts primarily consist of U.S. common stocks, which are valued using quoted market prices reported on nationally recognized securities exchanges. Equity securities. Equity securities consist of shares in Silence Therapeutics plc ("Silence"), for which quoted prices are available in an active market; therefore, the investment is classified as level 1 and is valued based on quoted market prices reported on an internationally recognized securities exchange. Deferred compensation liabilities. The Company maintains a non-qualified deferred compensation plan in the U.S., which permits eligible employees of the Company to defer a portion of their compensation. A recordkeeping account is set up for each participant and the participant chooses from a variety of funds for the deemed investment of their accounts. The recordkeeping accounts generally correspond to the funds offered in the Company's U.S. tax-qualified defined contribution retirement plan and the account balance fluctuates with the investment returns on those funds. Contingent consideration liabilities. As part of the acquisition of Stratatech, the Company provided contingent consideration to the prior shareholders of Stratatech, primarily in the form of regulatory filing and approval milestones associated with the deep partial thickness and full thickness indications associated with StrataGraft ® . For each indication, the Company is responsible for a payment upon acceptance of the Company's submission and another upon approval by the FDA. The Company assesses the likelihood and timing of making such payments at each balance sheet date. The fair value of the contingent payments was measured based on the net present value of a probability-weighted assessment. The Company determined the fair value of the contingent consideration associated with the acquisition of Stratatech to be $23.9 million and $19.1 million as of March 26, 2021 and December 25, 2020, respectively. As part of the acquisition of Ocera, the Company provided contingent consideration to the prior shareholders of Ocera in the form of both patient enrollment clinical study milestones and sales-based milestones associated with MNK-6105 and MNK-6106. During the three months ended March 26, 2021, the Company determined it will no longer pursue further development of this asset. The Company determined the fair value of the contingent consideration based on an option pricing model to be zero and $15.6 million as of March 26, 2021 and December 25, 2020, respectively. Contingent consideration liabilities were classified as LSTC in the unaudited condensed consolidated balance sheet as of March 26, 2021. The following table summarizes the activity for contingent consideration: Balance as of December 25, 2020 $ 34.7 Fair value adjustments (10.8) Balance as of March 26, 2021 $ 23.9 Financial Instruments Not Measured at Fair Value The following methods and assumptions were used by the Company in estimating fair values for financial instruments not measured at fair value as of March 26, 2021 and December 25, 2020: • The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and the majority of other current assets and liabilities approximate fair value because of their short-term nature. The Company classifies cash on hand and deposits in banks, including commercial paper, money market accounts and other investments it may hold from time to time, with an original maturity of three months or less, as cash and cash equivalents (level 1). The fair value of restricted cash was equivalent to its carrying value of $59.6 million and $56.4 million as of March 26, 2021 and December 25, 2020, (level 1), respectively. As of March 26, 2021, $23.4 million and $36.2 million of the restricted cash balance was included in prepaid and other current assets and other assets, respectively, on the unaudited condensed consolidated balance sheet. As of December 25, 2020, $20.2 million and $36.2 million of the restricted cash balance was included in prepaid and other current assets and other assets, respectively, on the consolidated balance sheet. • The Company's life insurance contracts are carried at cash surrender value, which is based on the present value of future cash flows under the terms of the contracts (level 3). Significant assumptions used in determining the cash surrender value include the amount and timing of future cash flows, interest rates and mortality charges. The fair value of these contracts approximates the carrying value of $52.6 million and $52.3 million as of March 26, 2021 and December 25, 2020, respectively. These contracts are included in other assets on the unaudited condensed consolidated balance sheets. • The carrying value of the Company's revolving credit facility approximates the fair value due to the short-term nature of this instrument, and is therefore classified as level 1. The Company's 4.875%, 5.75%, 4.75%, 5.625%, 5.50% and 10.00% first and second lien senior notes are classified as level 1, as quoted prices are available in an active market for these notes. Since the quoted market prices for the Company's term loans and 9.50% and 8.00% debentures are not available in an active market, they are classified as level 2 for purposes of developing an estimate of fair value. The following table presents the carrying values and estimated fair values of the Company's debt as of the end of each period: March 26, 2021 December 25, 2020 Carrying Fair Carrying Fair Level 1: 5.75% senior notes due August 2022 $ 610.3 $ 407.7 $ 610.3 $ 191.2 4.75% senior notes due April 2023 133.7 26.2 133.7 11.1 5.625% senior notes due October 2023 514.7 337.1 514.7 158.9 5.50% senior notes due April 2025 387.2 258.1 387.2 115.4 10.00% first lien senior notes due April 2025 495.0 553.4 495.0 528.4 10.00% second lien senior notes due April 2025 322.9 321.8 322.9 279.0 Revolving credit facility 900.0 900.0 900.0 900.0 Level 2: 9.50% debentures due May 2022 10.4 4.2 10.4 4.2 8.00% debentures due March 2023 4.4 1.3 4.4 1.3 Term loan due September 2024 1,411.2 1,394.7 1,505.2 1,386.9 Term loan due February 2025 374.6 369.8 399.5 367.9 Total Debt $ 5,164.4 $ 4,574.3 $ 5,283.3 $ 3,944.3 Concentration of Credit and Other Risks Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of accounts receivable. The Company generally does not require collateral from customers. A portion of the Company's accounts receivable outside the U.S. includes sales to government-owned or supported healthcare systems in several countries, which are subject to payment delays. Payment is dependent upon the financial stability and creditworthiness of those countries' national economies. The following table shows net sales attributable to distributors that accounted for 10.0% or more of the Company's total segment net sales: Three Months Ended March 26, March 27, CuraScript, Inc. 24.9 % 24.6 % The following table shows accounts receivable attributable to distributors that accounted for 10.0% or more of the Company's gross accounts receivable at the end of each period: March 26, December 25, AmerisourceBergen Corporation 33.2 % 33.6 % McKesson Corporation 15.9 18.2 CuraScript, Inc. 11.1 * Accounts receivable attributable to this distributor was less than 10.0% of total gross accounts receivable at the end of the respective period presented above. The following table shows net sales attributable to products that accounted for 10.0% or more of the Company's total segment net sales: Three Months Ended March 26, March 27, Acthar Gel 23.1 % 25.2 % INOmax 24.0 21.3 Ofirmev 11.2 Therakos 12.0 *

Segment Data

Segment Data	3 Months Ended
Segment Data	Mar. 26, 2021
Segment Reporting [Abstract]
Segment Data	13. Segment Data The Company operates in two reportable segments, which are further described below: • Specialty Brands includes innovative specialty pharmaceutical brands; and • Specialty Generics includes niche specialty generic drugs and APIs. Management measures and evaluates the Company's operating segments based on segment net sales and operating income. Management excludes corporate expenses from segment operating income. In addition, certain amounts that management considers to be non-recurring or non-operational are excluded from segment net sales and operating income because management and the chief operating decision maker evaluate the operating results of the segments excluding such items. These items may include, but are not limited to, depreciation and amortization, share-based compensation, net restructuring charges, non-restructuring impairment charges, separation costs, changes related to the Opioid-Related Litigation Settlement. During the three months ended September 25, 2020, the Company began excluding depreciation and share-based compensation from its evaluation of the operating results of its segments. As a result, prior period segment operating income has been recast to reflect this change on a comparable basis. Although these amounts are excluded from segment net sales and operating income, as applicable, they are included in reported consolidated net sales and operating income (loss) and are reflected in the reconciliations presented below. Selected information by reportable segment was as follows: Three Months Ended March 26, March 27, Net sales: Specialty Brands $ 408.4 $ 490.6 Specialty Generics 149.6 175.2 Net sales $ 558.0 $ 665.8 Operating loss: Specialty Brands $ 212.1 $ 220.5 Specialty Generics 31.7 63.2 Segment operating income 243.8 283.7 Unallocated amounts: Corporate and unallocated expenses (1) (22.6) (57.5) Depreciation and amortization (169.6) (223.1) Share-based compensation (3.6) (6.7) Restructuring charges, net (0.4) 1.8 Non-restructuring impairment charges (64.5) — Separation costs (2) (0.6) (21.3) Opioid-related litigation settlement gain (3) — 16.8 Operating loss $ (17.5) $ (6.3) (1) Includes administration expenses and certain compensation, legal, environmental and other costs not charged to the Company's reportable segments. (2) Represents costs included in SG&A expenses, primarily related to professional fees and costs incurred in preparation for the Chapter 11 proceedings. As of the Petition Date, professional fees directly related to the Chapter 11 proceedings that were previously reflected as separation costs are being classified on a go-forward basis as reorganization items, net. (3) Represents the change in the Settlement Warrants' fair value. Refer to Note 11 for further information. Net sales by product family within the Company's reportable segments were as follows: Three Months Ended March 26, March 27, Acthar Gel (1) $ 129.0 $ 167.6 INOmax 134.0 141.7 Ofirmev 12.8 74.9 Therakos 66.8 63.7 Amitiza (2) 61.4 41.1 Other 4.4 1.6 Specialty Brands 408.4 490.6 Hydrocodone (API) and hydrocodone-containing tablets 23.3 26.5 Oxycodone (API) and oxycodone-containing tablets 17.2 16.9 Acetaminophen (API) 45.5 44.1 Other controlled substances 58.1 83.6 Other 5.5 4.1 Specialty Generics 149.6 175.2 Net sales $ 558.0 $ 665.8 (1) The three months ended March 26, 2021 includes the prospective change to the Medicaid rebate calculation that began in June 2020, which impacted Acthar Gel net sales by $12.5 million. See Note 11 for further detail on the status of the Medicaid lawsuit. (2) Amitiza consists of both product net sales and royalties. Refer to Note 2 for further details on Amitiza's revenues.

Subsequent Events

Subsequent Events	3 Months Ended
Subsequent Events	Mar. 26, 2021
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events Bankruptcy Proceedings Certain bankruptcy proceeding matters occurred during the three months ended March 26, 2021 or prior, but had subsequent updates through the issuance of this report. See further discussion in Note 2. Commitments and Contingencies Certain litigation matters occurred during the three months ended March 26, 2021 or prior, but had subsequent updates through the issuance of this report. See further discussion in Note 11.

Reorganizations (Tables)

Reorganizations (Tables)	3 Months Ended
Reorganizations (Tables)	Mar. 26, 2021
Reorganizations [Abstract]
Schedule of Liabilities Subject to Compromise	Liabilities subject to compromise at the end of each period consisted of the following: March 26, December 25, Accounts payable (1) $ 52.9 $ 61.9 Accrued interest 35.2 35.2 Debt (2) 3,446.5 1,660.7 Medicaid lawsuit 638.9 638.9 Opioid-related litigation settlement liability 1,600.0 1,600.0 Other current and non-current liabilities (3) 108.1 163.5 Pension and postretirement benefits 32.6 32.4 Total liabilities subject to compromise $ 5,914.2 $ 4,192.6 (1) Pre-petition accounts payable balances have been repaid under effectuated trade agreements pursuant to the critical vendor motion approved by the Bankruptcy Court. (2) In accordance with the Joinder and Amendment to the RSA, $1,785.8 million of outstanding senior secured term loans have been reclassified to LSTC in the Company's unaudited condensed consolidated balance sheets as of March 26, 2021. (3) The decrease in other current and non-current liabilities was primarily attributable to the Bankruptcy Court's approval of the Company's rejection of its Bedminster facility lease, which resulted in a $34.8 million adjustment to the carrying value of the respective lease liability in LSTC to reflect the estimated allowed claim amount. The remaining decrease was primarily attributable to a decrease of $15.6 million in the fair value of contingent consideration related to an asset for which the Company is no longer pursuing further development. Refer to Note 12 for further information on the valuation of contingent consideration.
Non-debtor Entity Intercompany Balances	Non-debtor entity intercompany balances from/due to the debtor entities at the end of each period were: March 26, December 25, Intercompany receivables $ 135.4 $ 282.3 Intercompany payables 129.5 120.3
Schedule of Debtor Reorganization Items, net	Reorganization items, net, for the three months ended March 26, 2021 included the following: March 26, Professional fees $ 77.7 Debt valuation adjustments 16.3 Adjustments of other claims (0.5) Total reorganization items, net $ 93.5

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	3 Months Ended
Revenue from Contracts with Customers (Tables)	Mar. 26, 2021
Disaggregation of Revenue [Line Items]
Sales Reserves Rollforward	The following table reflects activity in the Company's sales reserve accounts: Rebates and Chargebacks Product Returns Other Sales Deductions Total Balance as of December 27, 2019 $ 295.8 $ 28.4 $ 13.2 $ 337.4 Provisions 457.8 3.8 13.7 475.3 Payments or credits (498.8) (6.1) (15.9) (520.8) Balance as of March 27, 2020 $ 254.8 $ 26.1 $ 11.0 $ 291.9 Balance as of December 25, 2020 $ 196.5 $ 26.6 $ 12.3 $ 235.4 Provisions (1) 488.0 25.7 13.0 526.7 Payments or credits (442.9) (10.0) (14.9) (467.8) Balance as of March 26, 2021 $ 241.6 $ 42.3 $ 10.4 $ 294.3 (1) Provisions for returns increased by $21.9 million driven by the Specialty Brands segment primarily related to a discrete return of product sold during the three months ended March 26, 2021.
Disaggregation of Revenue	Product sales transferred to customers at a point in time and over time were as follows: Three Months Ended March 26, March 27, Product sales transferred at a point in time 75.7 % 78.5 % Product sales transferred over time 24.3 21.5 Three Months Ended March 26, March 27, Royalty revenue $ 35.4 $ 15.6
Contract with Customer, Timing of Satisfaction of Performance Obligation and Payment	The following table includes estimated revenue from contracts extending greater than one year for certain of the Company's hospital products that are expected to be recognized in the future related to performance obligations that were unsatisfied or partially unsatisfied as of March 26, 2021: Remainder of Fiscal 2021 $ 70.9 Fiscal 2022 41.0 Fiscal 2023 9.9 Thereafter 0.3

Earnings per Share (Tables)

Earnings per Share (Tables)	3 Months Ended
Earnings per Share (Tables)	Mar. 26, 2021
Earnings Per Share [Abstract]
Schedule of Earnings per Share	The weighted-average number of shares outstanding used in the computations of both basic and diluted loss per share were as follows ( in millions ): Three Months Ended March 26, March 27, Basic 84.6 84.2

Inventories (Tables)

Inventories (Tables)	3 Months Ended
Inventories (Tables)	Mar. 26, 2021
Inventory, Net [Abstract]
Schedule of Inventories	Inventories were comprised of the following at the end of each period: March 26, December 25, Raw materials and supplies $ 58.0 $ 58.1 Work in process 205.9 200.7 Finished goods 99.5 86.1 $ 363.4 $ 344.9

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	3 Months Ended
Property, Plant and Equipment (Tables)	Mar. 26, 2021
Property, Plant and Equipment
Property, Plant and Equipment	The gross carrying amount and accumulated depreciation of property, plant and equipment were comprised of the following at the end of each period: March 26, December 25, 2020 Property, plant and equipment, gross $ 1,874.2 $ 1,910.9 Less: accumulated depreciation (1,079.8) (1,077.8) Property, plant and equipment, net $ 794.4 $ 833.1
Depreciation of Fixed Assets	Depreciation expense was as follows: Three Months Ended March 26, March 27, Depreciation expense $ 24.3 $ 25.5

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
Goodwill and Intangible Assets (Tables)	Mar. 26, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The gross carrying amount and accumulated amortization of intangible assets were comprised of the following at the end of each period: March 26, 2021 December 25, 2020 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortizable: Completed technology $ 10,394.6 $ 4,730.0 $ 10,394.6 $ 4,586.6 License agreements 120.1 79.1 120.1 78.1 Trademarks 77.7 24.4 77.7 23.5 Total $ 10,592.4 $ 4,833.5 $ 10,592.4 $ 4,688.2 Non-Amortizable: Trademarks $ 35.0 $ 35.0 In-process research and development 180.8 245.3 Total $ 215.8 $ 280.3
Intangible Asset Amortization Expense	Intangible asset amortization expense was as follows: Three Months Ended March 26, March 27, Amortization expense $ 145.3 $ 197.6
Schedule of Future Amortization Expense, Intangible Assets	The estimated aggregate amortization expense on intangible assets owned by the Company is expected to be as follows: Remainder of Fiscal 2021 $ 435.8 Fiscal 2022 581.1 Fiscal 2023 581.1 Fiscal 2024 581.1 Fiscal 2025 579.6

Debt (Tables)

Debt (Tables)	3 Months Ended
Debt (Tables)	Mar. 26, 2021
Debt Disclosure [Abstract]
Schedule of Debt including Capital Lease Obligation	Debt was comprised of the following at the end of each period: March 26, 2021 December 25, 2020 Principal Unamortized Discount and Debt Issuance Costs (1) Principal Unamortized Discount and Debt Issuance Costs (1) Secured debt: Term loan due September 2024 $ 1,411.2 $ — $ 1,505.2 $ 12.3 Term loan due February 2025 374.6 — 399.5 5.0 10.00% first lien senior notes due April 2025 495.0 7.3 495.0 7.7 10.00% second lien senior notes due April 2025 322.9 7.6 322.9 8.0 Revolving credit facility 900.0 1.3 900.0 1.7 Total secured debt 3,503.7 16.2 3,622.6 34.7 Unsecured debt: 9.50% debentures due May 2022 10.4 — 10.4 — 5.75% senior notes due August 2022 610.3 — 610.3 — 8.00% debentures due March 2023 4.4 — 4.4 — 4.75% senior notes due April 2023 133.7 — 133.7 — 5.625% senior notes due October 2023 514.7 — 514.7 — 5.50% senior notes due April 2025 387.2 — 387.2 — Total unsecured debt 1,660.7 — 1,660.7 — Total debt, prior to reclassification to liabilities subject to compromise 5,164.4 16.2 5,283.3 34.7 Less: Current portion (1,717.9) (16.2) (3,622.6) (34.7) Less: Amounts reclassified to liabilities subject to compromise (2) (3,446.5) — (1,660.7) — Total long-term debt, net of current portion $ — $ — $ — $ — (1) As a result of the Company's Chapter 11 Cases, the Company expensed $16.3 million of unamortized discount and debt issuance costs, net, recorded in reorganization items, net in the unaudited condensed consolidated statement of operations during the three months ended March 26, 2021. (2) In connection with the Company’s Chapter 11 Cases, $3,446.5 million and $1,660.7 million outstanding secured and unsecured debt instruments have been reclassified to LSTC in the Company's unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020, respectively. Up to the date of reclassification to LSTC, the Company continued to accrue interest expense in relation to these debt instruments reclassified to LSTC. Refer to Note 2 for further information.
Schedule of Applicable Interest Rate on Variable-rate Debt	As of March 26, 2021, the applicable interest rate and outstanding borrowings on the Company's variable-rate debt instruments were as follows: Applicable interest rate Outstanding borrowings Term loan due September 2024 (1) 6.00 % $ 1,411.2 Term loan due February 2025 (1) 6.25 374.6 Revolving credit facility 4.47 900.0

Financial Instruments and Fai_2

Financial Instruments and Fair Value Measurements (Tables)	3 Months Ended
Financial Instruments and Fair Value Measurements (Tables)	Mar. 26, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis	The following tables provide a summary of the significant assets and liabilities that are measured at fair value on a recurring basis at the end of each period: March 26, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 32.9 $ 23.1 $ 9.8 $ — Equity securities 39.5 39.5 — — $ 72.4 $ 62.6 $ 9.8 $ — Liabilities: Deferred compensation liabilities $ 32.1 $ — $ 32.1 $ — Contingent consideration and acquired contingent liabilities 23.9 — — 23.9 $ 56.0 $ — $ 32.1 $ 23.9 December 25, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 33.0 $ 23.5 $ 9.5 $ — Equity securities 31.1 31.1 — — $ 64.1 $ 54.6 $ 9.5 $ — Liabilities: Deferred compensation liabilities $ 38.0 $ — $ 38.0 $ — Contingent consideration and acquired contingent liabilities 34.7 — — 34.7 $ 72.7 $ — $ 38.0 $ 34.7
Schedule of Reconciliation of Changes in Fair Value of Contingent Liabilities	The following table summarizes the activity for contingent consideration: Balance as of December 25, 2020 $ 34.7 Fair value adjustments (10.8) Balance as of March 26, 2021 $ 23.9
Schedule of Carrying Amount and Fair Value of Long-term Debt	The following table presents the carrying values and estimated fair values of the Company's debt as of the end of each period: March 26, 2021 December 25, 2020 Carrying Fair Carrying Fair Level 1: 5.75% senior notes due August 2022 $ 610.3 $ 407.7 $ 610.3 $ 191.2 4.75% senior notes due April 2023 133.7 26.2 133.7 11.1 5.625% senior notes due October 2023 514.7 337.1 514.7 158.9 5.50% senior notes due April 2025 387.2 258.1 387.2 115.4 10.00% first lien senior notes due April 2025 495.0 553.4 495.0 528.4 10.00% second lien senior notes due April 2025 322.9 321.8 322.9 279.0 Revolving credit facility 900.0 900.0 900.0 900.0 Level 2: 9.50% debentures due May 2022 10.4 4.2 10.4 4.2 8.00% debentures due March 2023 4.4 1.3 4.4 1.3 Term loan due September 2024 1,411.2 1,394.7 1,505.2 1,386.9 Term loan due February 2025 374.6 369.8 399.5 367.9 Total Debt $ 5,164.4 $ 4,574.3 $ 5,283.3 $ 3,944.3
Schedules of Concentration of Risk	The following table shows net sales attributable to distributors that accounted for 10.0% or more of the Company's total segment net sales: Three Months Ended March 26, March 27, CuraScript, Inc. 24.9 % 24.6 % The following table shows accounts receivable attributable to distributors that accounted for 10.0% or more of the Company's gross accounts receivable at the end of each period: March 26, December 25, AmerisourceBergen Corporation 33.2 % 33.6 % McKesson Corporation 15.9 18.2 CuraScript, Inc. 11.1 * Accounts receivable attributable to this distributor was less than 10.0% of total gross accounts receivable at the end of the respective period presented above. The following table shows net sales attributable to products that accounted for 10.0% or more of the Company's total segment net sales: Three Months Ended March 26, March 27, Acthar Gel 23.1 % 25.2 % INOmax 24.0 21.3 Ofirmev 11.2 Therakos 12.0 *

Segment Data (Tables)

Segment Data (Tables)	3 Months Ended
Segment Data (Tables)	Mar. 26, 2021
Segment Reporting [Abstract]
Schedule of Segment Reporting Information by Reportable Segment	Selected information by reportable segment was as follows: Three Months Ended March 26, March 27, Net sales: Specialty Brands $ 408.4 $ 490.6 Specialty Generics 149.6 175.2 Net sales $ 558.0 $ 665.8 Operating loss: Specialty Brands $ 212.1 $ 220.5 Specialty Generics 31.7 63.2 Segment operating income 243.8 283.7 Unallocated amounts: Corporate and unallocated expenses (1) (22.6) (57.5) Depreciation and amortization (169.6) (223.1) Share-based compensation (3.6) (6.7) Restructuring charges, net (0.4) 1.8 Non-restructuring impairment charges (64.5) — Separation costs (2) (0.6) (21.3) Opioid-related litigation settlement gain (3) — 16.8 Operating loss $ (17.5) $ (6.3) (1) Includes administration expenses and certain compensation, legal, environmental and other costs not charged to the Company's reportable segments. (2) Represents costs included in SG&A expenses, primarily related to professional fees and costs incurred in preparation for the Chapter 11 proceedings. As of the Petition Date, professional fees directly related to the Chapter 11 proceedings that were previously reflected as separation costs are being classified on a go-forward basis as reorganization items, net. (3) Represents the change in the Settlement Warrants' fair value. Refer to Note 11 for further information.
Schedule of Net Sales from External Customers by Products	Net sales by product family within the Company's reportable segments were as follows: Three Months Ended March 26, March 27, Acthar Gel (1) $ 129.0 $ 167.6 INOmax 134.0 141.7 Ofirmev 12.8 74.9 Therakos 66.8 63.7 Amitiza (2) 61.4 41.1 Other 4.4 1.6 Specialty Brands 408.4 490.6 Hydrocodone (API) and hydrocodone-containing tablets 23.3 26.5 Oxycodone (API) and oxycodone-containing tablets 17.2 16.9 Acetaminophen (API) 45.5 44.1 Other controlled substances 58.1 83.6 Other 5.5 4.1 Specialty Generics 149.6 175.2 Net sales $ 558.0 $ 665.8 (1) The three months ended March 26, 2021 includes the prospective change to the Medicaid rebate calculation that began in June 2020, which impacted Acthar Gel net sales by $12.5 million. See Note 11 for further detail on the status of the Medicaid lawsuit. (2) Amitiza consists of both product net sales and royalties. Refer to Note 2 for further details on Amitiza's revenues.

Reorganizations (Details)

Reorganizations (Details) $ in Millions	Mar. 26, 2021USD ($)	Mar. 19, 2021USD ($)	Mar. 10, 2021USD ($)	Oct. 11, 2020USD ($)	Dec. 25, 2020USD ($)numberOfPlaintiffs	Mar. 26, 2021USD ($)	Mar. 27, 2020USD ($)	May 04, 2021action	Dec. 25, 2020USD ($)
Reorganizations [Line Items]
Restructuring Support Agreement, MSGE Support Group \| numberOfPlaintiffs					1,300
Restructuring Support Agreement, Common Stock Share Percentage Reorganized New Company				100.00%
Accrued interest	$ 27.8				$ 26.9	$ 27.8			$ 26.9
Cash Paid, Reorganization items						33.7
Restructuring Support Agreement, Proposed Settlement of General Unsecured Claims				$ 150
Restructuring Support Agreement, Proposed Notes Reduction				1,300
Subsequent Event [Member]
Reorganizations [Line Items]
Bankruptcy Claims, Number Claims Filed \| action								49,000
Opioid Claimant Trust [Member]
Reorganizations [Line Items]
Restructuring Support Agreement Proposed Settlement				1,600
Restructuring Support Agreement, Equity Value of Reorganized Debtors				1,551
Restructuring Support Agreement Proposed Settlement, Year Three through Eight				150
Restructuring Support Agreement ProposedSettlement, Payment Year One and Two				200
Restructuring Support Agreement Proposed Settlement, Upfront Payment				$ 450
Opioid Claimant Trust [Member] \| Other Ownership Interest [Member]
Reorganizations [Line Items]
Restructuring Support Agreement, Warrants Common Stock Share Percentage Reorganized New Company				19.99%
Medicaid Lawsuit [Member]
Reorganizations [Line Items]
Restructuring Support Agreement Proposed Settlement				$ 260
Medicaid Lawsuit [Member] \| Maximum
Reorganizations [Line Items]
Loss Contingency, Estimate of Possible Loss				640
Term Loans due Sept 2024 and Feb 2025
Reorganizations [Line Items]
Repayments of Long-term Debt		$ 114
Proposed Debt Instrument Term			5 years 9 months
Unsecured Debt
Reorganizations [Line Items]
Interest Paid, Excluding Capitalized Interest, Operating Activities						0	$ 17.7
Accrued interest	$ 17.7					$ 17.7
Restructuring Support Agreement [Member] \| Opioid Claimant Trust [Member]
Reorganizations [Line Items]
Restructuring Support Agreement Proposed Settlement, Year Three through Eight				150
Restructuring Support Agreement [Member] \| Term Loans due Sept 2024 and Feb 2025
Reorganizations [Line Items]
Ad Hoc Lender Aggregate Principal Amount			$ 1,300
Secured Debt
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)						200.00%
Adequate Protection Payment, Expense							$ 14.5		11.7
Adequate Protection Payment, Cash Paid						$ 13.8			$ 7.8
Restructuring Support Agreement, Proposed Long-Term Debt				$ 375
Restructuring Support Agreement, Proposed Debt, Term				7 years
Secured Debt \| Term Loan due 2024
Reorganizations [Line Items]
Proposed Debt Instrument Basis Spread On Variable Rate	5.25%					5.25%
Secured Debt \| Term Loan due 2025
Reorganizations [Line Items]
Proposed Debt Instrument Basis Spread On Variable Rate			5.50%
Unsecured Debt \| 5.625% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.625%					5.625%
Unsecured Debt \| Restructuring Support Agreement [Member]
Reorganizations [Line Items]
Holders of Principal Debt, Percentage				84.00%
Senior Notes \| 5.75% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.75%					5.75%
Senior Notes \| 5.50% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.50%					5.50%
Senior Notes \| 10.00% Second Lien Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				10.00%
Senior Notes \| 4.75% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.75%					4.75%
Debentures \| 9.50% Debenture
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	9.50%					9.50%
Debentures \| 8.00% Debenture
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8.00%					8.00%
Term Loans due Sept 2024 and Feb 2025
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)	250.00%

Liabilities Subject to Compromi

Liabilities Subject to Compromise (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 26, 2021	Dec. 25, 2020
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise		$ 5,914.2	$ 4,192.6
Lease rejection
Schedule of Liabilities Subject to Compromise [Line Items]
Increase (Decrease) Other current and non-current liabilities		34.8
Contingent Consideration
Schedule of Liabilities Subject to Compromise [Line Items]
Increase (Decrease) Other current and non-current liabilities		15.6
Accounts Payable
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise		52.9	61.9
Interest Payable, Current
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise		35.2	35.2
Long-term Debt
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise	[1]	3,446.5	1,660.7
Long-term Debt \| Term Loans due Sept 2024 and Feb 2025
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise		1,785.8
Medicaid Lawsuit [Member]
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise		638.9	638.9
Opioid-related litigation settlement liability
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise		1,600	1,600
Other current and non-current liabilities
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise		108.1	163.5
Liability, Defined Benefit Plan, Noncurrent
Schedule of Liabilities Subject to Compromise [Line Items]
Liabilities Subject to Compromise		$ 32.6	$ 32.4

[1]	In connection with the Company’s Chapter 11 Cases, $3,446.5 million and $1,660.7 million outstanding secured and unsecured debt instruments have been reclassified to LSTC in the Company's unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020, respectively. Up to the date of reclassification to LSTC, the Company continued to accrue interest expense in relation to these debt instruments reclassified to LSTC. Refer to Note 2 for further information

Reorganization Items, Net (Deta

Reorganization Items, Net (Details) - USD ($) $ in Millions	3 Months Ended
Reorganization Items, Net (Details) - USD ($) $ in Millions	Mar. 26, 2021	Mar. 27, 2020
Schedule of Reorganization Items, net [Line Items]
Debtor Reorganization Items, Legal and Advisory Professional Fees	$ 77.7
Debtor Reorganization Items, Write-off of Debt Issuance Costs and Debt Discounts	16.3
Debtor Reorganization Items, Provision for Expected Allowed Claims	(0.5)
Reorganization Items	93.5	$ 0
Cash Paid, Reorganization items	33.7
Lease rejection
Schedule of Reorganization Items, net [Line Items]
Increase (Decrease) Other current and non-current liabilities	34.8
Contingent Consideration
Schedule of Reorganization Items, net [Line Items]
Increase (Decrease) Other current and non-current liabilities	$ 15.6

Non-debtor Entity Intercompany

Non-debtor Entity Intercompany Balances (Details) - USD ($) $ in Millions	Mar. 26, 2021	Dec. 25, 2020
Schedule of Non-debtor Entity Intercompany Balances [Line Items]
Non-Debtor Intercompany Receivables From Debtor Entities	$ 135.4	$ 282.3
Non-Debtor Intercompany Payables to Debtor Entities	$ 129.5	$ 120.3

Revenue from Contracts with C_3

Revenue from Contracts with Customers Future Performance Obligations (Details) $ in Millions	Mar. 26, 2021USD ($)
Remainder of Fiscal 2021
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 70.9
Fiscal 2022
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	41
Fiscal 2023
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	9.9
Thereafter
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 0.3

Revenue from Contracts with C_4

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2021		Mar. 27, 2020	Dec. 25, 2020	Dec. 27, 2019
Disaggregation of Revenue [Line Items]
Revenue Reserves	$ 294.3		$ 291.9	$ 235.4	$ 337.4
Revenue Reserve Provision	526.7		475.3
Revenue Reserve Payments or Credits	(467.8)		(520.8)
Change in Product Returns provision	21.9
Capitalized Contract Cost, Gross	27			25.8
Capitalized Contract Cost, Amortization	1.4		1.5
Net sales	$ 558		$ 665.8
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue	75.70%		78.50%
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue	24.30%		21.50%
Royalty [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 35.4		$ 15.6
Rebates and Chargebacks [Member]
Disaggregation of Revenue [Line Items]
Revenue Reserves	241.6		254.8	196.5	295.8
Revenue Reserve Provision	488		457.8
Revenue Reserve Payments or Credits	(442.9)		(498.8)
Allowance for Sales Returns [Member]
Disaggregation of Revenue [Line Items]
Revenue Reserves	42.3		26.1	26.6	28.4
Revenue Reserve Provision	25.7	[1]	3.8
Revenue Reserve Payments or Credits	(10)		(6.1)
Other Sales Deductions [Member]
Disaggregation of Revenue [Line Items]
Revenue Reserves	10.4		11	$ 12.3	$ 13.2
Revenue Reserve Provision	13		13.7
Revenue Reserve Payments or Credits	$ (14.9)		$ (15.9)
Minimum
Disaggregation of Revenue [Line Items]
Royalty Rate Percentage	18.00%
Maximum
Disaggregation of Revenue [Line Items]
Royalty Rate Percentage	26.00%

[1]	Provisions for returns increased by $21.9 million driven by the Specialty Brands segment primarily related to a discrete return of product sold during the three months ended March 26, 2021.

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Mar. 26, 2021	Mar. 27, 2020	Dec. 25, 2020
Income Taxes [Line Items]
Income tax benefit	$ (16.4)	$ (18.9)
Increase (decrease) tax benefit	(2.5)
(Loss) income from continuing operations before income taxes	$ (160.6)	$ (75.6)
Effective tax rate	10.20%	25.00%
Current Income Tax Expense (Benefit)	$ 13	$ (22.4)
Deferred Income Tax Expense (Benefit)	3.4	$ (3.5)
Income Taxes Paid, Net	8.1		$ 39.9
Unrecognized tax benefits	356.2		349
Unrecognized tax benefits, net increase	7.2
Unrecognized tax benefits, which if favorably settled would benefit the effective tax rate	80.9
Interest accrued on unrecognized tax benefits	19.8		$ 16.7
Unrecognized tax benefits that would impact effective tax rate, upper bound of change	41.7
Income tax penalties and interest accrued that would impact effective tax rate, upper bound of change	9.8
Increase (Decrease) Tax Expense (Benefit), Change in Operating Income	15.4
Increase (Decrease), Tax Expense (Benefit), CARES Act	11
Increase (Decrease), Tax Expense (Benefit), Uncertain Tax Positions	8
Increase (Decrease), Income Tax Expense (Benefit), Separation Costs, Reorganization Items, and Restructuring Charges	$ 1.1

Earnings per Share (Details)

Earnings per Share (Details) - shares shares in Millions	3 Months Ended
Earnings per Share (Details) - shares shares in Millions	Mar. 26, 2021	Mar. 27, 2020
Earnings Per Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	5.5	5.8
Weighted-average shares outstanding - basic (in shares)	84.6	84.2
Weighted-average shares outstanding - diluted (in shares)	84.6	84.2

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Mar. 26, 2021	Dec. 25, 2020
Raw materials and supplies	$ 58	$ 58.1
Work in process	205.9	200.7
Finished goods	99.5	86.1
Inventory, Net, Total	$ 363.4	$ 344.9

Property, Plant and Equipment_2

Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Millions	Mar. 26, 2021	Dec. 25, 2020
Property, Plant and Equipment
Property, plant and equipment, gross	$ 1,874.2	$ 1,910.9
Less: accumulated depreciation	(1,079.8)	(1,077.8)
Property, plant and equipment, net	$ 794.4	$ 833.1

Property, Plant and Equipment D

Property, Plant and Equipment Depreciation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2021	Mar. 27, 2020
Property, Plant and Equipment
Depreciation	$ 24.3	$ 25.5

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2021	Mar. 27, 2020	Dec. 25, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Non-restructuring impairment charges	$ 64.5	$ 0
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	10,592.4		$ 10,592.4
Accumulated amortization	4,833.5		4,688.2
Intangible assets, net	5,974.7		6,184.5
Non-Amortizable intangible assets, gross	215.8		280.3
Non-restructuring impairment charges	64.5	$ 0
Trademarks
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	35		35
In-process Research and Development
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	180.8		245.3
Completed Technology
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	10,394.6		10,394.6
Accumulated amortization	4,730		4,586.6
Trademarks
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	77.7		77.7
Accumulated amortization	24.4		23.5
Licensing Agreements [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	120.1		120.1
Accumulated amortization	79.1		78.1
Terlipressin [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Intangible assets, net	81		$ 81
MNK-6105 [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Non-restructuring impairment charges	64.5
Schedule of Intangible Asset by Major Class [Line Items]
Non-restructuring impairment charges	$ 64.5

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Schedule of Intangible Asset Amortization Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2021	Mar. 27, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of Intangible Assets	$ 145.3	$ 197.6

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets (Schedule of Future Amortization Expense, Intangible Assets) (Details) $ in Millions	Mar. 26, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of Fiscal 2021	$ 435.8
Fiscal 2022	581.1
Fiscal 2023	581.1
Fiscal 2024	581.1
Fiscal 2025	$ 579.6

Debt (Details)

Debt (Details) - USD ($) $ in Millions		Mar. 26, 2021		Dec. 25, 2020
Current maturities of long-term debt
Debt Issuance Costs, Current, Net		$ 16.2		$ 34.7
Long-term Debt, Current Maturities		1,717.9		3,622.6
Long-term debt
Long-term Debt		0		0
Debt Issuance Costs		0		0
Total Debt Issuance Costs		16.2		34.7
Secured Debt		3,503.7		3,622.6
Unsecured Debt		1,660.7		1,660.7
Total Debt		5,164.4		5,283.3
Liabilities Subject to Compromise		(5,914.2)		(4,192.6)
Long-term Debt
Long-term debt
Liabilities Subject to Compromise	[1]	(3,446.5)		(1,660.7)
Liabilities Subject to Compromise
Long-term debt
Total Debt Issuance Costs	[1]	0		0
Unsecured Debt
Long-term debt
Total Debt Issuance Costs		0		0
Secured Debt
Long-term debt
Total Debt Issuance Costs		16.2		34.7
Term Loan due 2025
Long-term debt
Secured Debt		374.6		399.5
Term Loan due 2025 \| Secured Debt
Long-term debt
Total Debt Issuance Costs		0	[2]	5
Term Loan due 2024
Long-term debt
Secured Debt		1,411.2		1,505.2
Term Loan due 2024 \| Secured Debt
Long-term debt
Total Debt Issuance Costs		0	[2]	12.3
9.50% Debenture
Long-term debt
Unsecured Debt		10.4		10.4
9.50% Debenture \| Unsecured Debt
Long-term debt
Total Debt Issuance Costs		0		0
5.75% Senior Notes
Long-term debt
Unsecured Debt		610.3		610.3
5.75% Senior Notes \| Unsecured Debt
Long-term debt
Total Debt Issuance Costs		0		0
8.00% Debenture
Long-term debt
Unsecured Debt		4.4		4.4
8.00% Debenture \| Unsecured Debt
Long-term debt
Total Debt Issuance Costs		0		0
4.75% Senior Notes
Long-term debt
Unsecured Debt		133.7		133.7
4.75% Senior Notes \| Unsecured Debt
Long-term debt
Total Debt Issuance Costs		0		0
5.625% Senior Notes
Long-term debt
Unsecured Debt		514.7		514.7
5.625% Senior Notes \| Unsecured Debt
Long-term debt
Total Debt Issuance Costs		0		0
5.50% Senior Notes
Long-term debt
Unsecured Debt		387.2		387.2
5.50% Senior Notes \| Unsecured Debt
Long-term debt
Total Debt Issuance Costs		0		0
10.00% Second Lien Senior Notes
Long-term debt
Secured Debt		322.9		322.9
10.00% Second Lien Senior Notes \| Secured Debt
Long-term debt
Total Debt Issuance Costs		7.6		8
10.00% First Lien Senior Notes
Long-term debt
Secured Debt		495		495
10.00% First Lien Senior Notes \| Secured Debt
Long-term debt
Total Debt Issuance Costs		7.3		7.7
2017 Revolving Credit Facility
Long-term debt
Secured Debt		900		900
2017 Revolving Credit Facility \| Secured Debt
Long-term debt
Total Debt Issuance Costs		$ 1.3		$ 1.7

[1]	In connection with the Company’s Chapter 11 Cases, $3,446.5 million and $1,660.7 million outstanding secured and unsecured debt instruments have been reclassified to LSTC in the Company's unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020, respectively. Up to the date of reclassification to LSTC, the Company continued to accrue interest expense in relation to these debt instruments reclassified to LSTC. Refer to Note 2 for further information
[2]	As a result of the Company's Chapter 11 Cases, the Company expensed $16.3 million of unamortized discount and debt issuance costs, net, recorded in reorganization items, net in the unaudited condensed consolidated statement of operations during the three months ended March 26, 2021.

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Millions		Mar. 26, 2021	Mar. 26, 2021	Dec. 25, 2020
Debt Instrument
Debtor Reorganization Items, Write-off of Debt Issuance Costs and Debt Discounts			$ 16.3
Liabilities Subject to Compromise		$ (5,914.2)	(5,914.2)	$ (4,192.6)
Long-term Debt
Debt Instrument
Liabilities Subject to Compromise	[1]	(3,446.5)	$ (3,446.5)	$ (1,660.7)
Secured Debt
Debt Instrument
Debt Instrument, Interest Rate, Increase (Decrease)			200.00%
Unsecured Debt \| 2017 Revolving Credit Facility
Debt Instrument
Line of Credit Facility, Maximum Borrowing Capacity		$ 900	$ 900
Term Loans due Sept 2024 and Feb 2025
Debt Instrument
Debt Instrument, Interest Rate, Increase (Decrease)		250.00%
Term Loans due Sept 2024 and Feb 2025 \| Long-term Debt
Debt Instrument
Liabilities Subject to Compromise		$ (1,785.8)	$ (1,785.8)

[1]	In connection with the Company’s Chapter 11 Cases, $3,446.5 million and $1,660.7 million outstanding secured and unsecured debt instruments have been reclassified to LSTC in the Company's unaudited condensed consolidated balance sheets as of March 26, 2021 and December 25, 2020, respectively. Up to the date of reclassification to LSTC, the Company continued to accrue interest expense in relation to these debt instruments reclassified to LSTC. Refer to Note 2 for further information

Debt (Schedule of Applicable In

Debt (Schedule of Applicable Interest Rates on Variable-rate Debt) (Details) - USD ($) $ in Millions	Mar. 26, 2021	Dec. 25, 2020
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Secured Debt	$ 3,503.7	$ 3,622.6
2017 Revolving Credit Facility
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Interest rate	4.47%
Secured Debt	$ 900	900
Term Loan due 2025
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Secured Debt	$ 374.6	399.5
Term Loan due 2025 \| Secured Debt
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time	6.25%
Term Loan due 2024
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Secured Debt	$ 1,411.2	$ 1,505.2
Term Loan due 2024 \| Secured Debt
Schedule of Applicable Interest Rate on Variable-rate Debt [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time	6.00%

Guarantees (Details)

Guarantees (Details) - USD ($) $ in Millions	3 Months Ended
Guarantees (Details) - USD ($) $ in Millions	Mar. 26, 2021	Dec. 25, 2020
Others
Guarantor Obligations [Line Items]
Maximum future payments	$ 34.5
Asset Pledged as Collateral [Member]
Guarantor Obligations [Line Items]
Restricted Cash	$ 40.6
Mallinckrodt Baker \| Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor obligations, obligation term	17 years
Maximum future payments	$ 70.2
Escrow Deposit	30
Mallinckrodt Baker \| Indemnification Agreement \| Other current and non-current liabilities
Guarantor Obligations [Line Items]
Guarantors obligation	15.2	$ 15.4
Mallinckrodt Baker \| Indemnification Agreement \| Other current and non-current assets
Guarantor Obligations [Line Items]
Escrow Deposit	19
Mallinckrodt Baker \| Environmental, Health and Safety Matters \| Indemnification Agreement \| Other current and non-current liabilities
Guarantor Obligations [Line Items]
Guarantors obligation	$ 12.4	$ 12.7

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) $ / shares in Units, $ in Millions	Oct. 12, 2020USD ($)	Oct. 11, 2020USD ($)	Feb. 25, 2020USD ($)$ / shares	Mar. 26, 2021USD ($)lawsuit	Dec. 25, 2020USD ($)	Mar. 27, 2020USD ($)	Dec. 25, 2020USD ($)
Loss Contingencies [Line Items]
Medicaid lawsuit (Note 11)							$ 641.1
Settlement Warrants, Fair Value Disclosure				$ 0	$ 0		0
Liabilities Subject to Compromise				5,914.2	4,192.6		4,192.6
Sales [Member]
Loss Contingencies [Line Items]
Medicaid lawsuit (Note 11)							536
Operating Expenses
Loss Contingencies [Line Items]
Medicaid lawsuit (Note 11)						$ 105.1	105.1
Medicaid Lawsuit [Member]
Loss Contingencies [Line Items]
Liabilities Subject to Compromise				638.9	638.9		638.9
Boston Civil Investigative Demand [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual				0
Medicaid Lawsuit [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Total	$ 260
Loss Contingency Accrual				0
Medicaid Lawsuit [Member] \| Maximum
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss		$ 640
Track 1 Cases [Member]
Loss Contingencies [Line Items]
Payments for Legal Settlements					24
Loss Contingency Accrual, Product Liability, Gross				6
Loss Contingency, Accrual, Noncurrent				$ 0.5
Opioid crisis [Member] \| Cities, Counties, and/or Other Government-related Persons/Entities [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs \| lawsuit				2,615
Opioid crisis [Member] \| Hospitals, Health Systems, Unions, Health and Welfare Fund or Third-Party Payers [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs \| lawsuit				270
Opioid crisis [Member] \| Individuals [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs \| lawsuit				124
Opioid crisis [Member] \| Schools and School Boards [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs \| lawsuit				6
Opioid crisis [Member] \| State Attorney Generals [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs \| lawsuit				17
Opioid Claimant Trust [Member]
Loss Contingencies [Line Items]
Warrant, Exercise Price \| $ / shares			$ 3.15
Restructuring Support Agreement Proposed Settlement, Year Three through Eight		150
Opioid Claimant Trust [Member] \| Restructuring Support Agreement [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Amount Awarded to Other Party, Settlement Closing Amount		450
Litigation Settlement, Amount Awarded to Other Party, Post Closing Settlement Amount, Year One & Two		200
Restructuring Support Agreement Proposed Settlement, Year Three through Eight		150
Opioid Claimant Trust [Member] \| Maximum
Loss Contingencies [Line Items]
Loss Contingency Accrual			$ 1,600	$ 1,600	$ 1,600		$ 1,600
Opioid Claimant Trust [Member] \| Maximum \| Restructuring Support Agreement [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual		1,600
Equity Value of Opioid Claimants' Ownership		$ 1,551
Senior Notes \| 5.75% Senior Notes
Loss Contingencies [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				5.75%
Senior Notes \| 10.00% Second Lien Senior Notes
Loss Contingencies [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		10.00%
Other Ownership Interest [Member] \| Opioid Claimant Trust [Member] \| Maximum
Loss Contingencies [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners			19.99%
Other Ownership Interest [Member] \| Opioid Claimant Trust [Member] \| Maximum \| Restructuring Support Agreement [Member]
Loss Contingencies [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		19.99%

Financial Instruments and Fai_3

Financial Instruments and Fair Value Measurements (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 25, 2020	Mar. 26, 2021	Dec. 25, 2020	Oct. 11, 2020
Debentures \| 8.00% Debenture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		8.00%
Debentures \| 9.50% Debenture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		9.50%
Senior Notes \| 4.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		4.75%
Senior Notes \| 5.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.75%
Senior Notes \| 5.50% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.50%
Senior Notes \| 10.00% Second Lien Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage				10.00%
Unsecured Debt \| 5.625% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.625%
Level 3 \| Other current and non-current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash surrender value of life insurance		$ 52.6	$ 52.3
Level 3 \| StrataGraft [Member] \| Recurring \| Stratatech
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent liability		23.9	19.1
Level 3 \| MNK-6105 [Member] \| Recurring \| Ocera [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent consideration		$ 0	15.6
Level 2 \| Debentures \| 8.00% Debenture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		8.00%
Level 2 \| Debentures \| 9.50% Debenture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		9.50%
Level 1 \| Senior Notes \| 4.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		4.75%
Level 1 \| Senior Notes \| 5.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.75%
Level 1 \| Senior Notes \| 4.88% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		4.875%
Level 1 \| Senior Notes \| 5.50% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.50%
Level 1 \| Senior Notes \| 10.00% Second Lien Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		10.00%
Level 1 \| Unsecured Debt \| 5.625% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Interest Rate, Stated Percentage		5.625%
Indemnification Agreement \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Restricted Cash and Cash Equivalents		$ 59.6	56.4
Indemnification Agreement \| Level 1 \| Other Assets, Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Restricted Cash and Cash Equivalents		23.4	20.2
Indemnification Agreement \| Level 1 \| Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Restricted Cash and Cash Equivalents		36.2	36.2
Contingent Liabilities \| Level 3 \| Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value adjustment		10.8
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value		$ 23.9	$ 34.7
Opioid Claimant Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Warrant, Exercise Price	$ 3.15
Other Ownership Interest [Member] \| Opioid Claimant Trust [Member] \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	19.99%

Financial Instruments and Fai_4

Financial Instruments and Fair Value Measurements (Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 26, 2021	Dec. 25, 2020
Assets:
Other Assets, Fair Value Disclosure	$ 39.5	$ 31.1
Assets, Fair Value Disclosure	72.4	64.1
Liabilities:
Settlement Warrants, Fair Value Disclosure	0	0
Recurring
Assets:
Rabbi Trust Investments, Fair Value Disclosure	32.9	33
Liabilities:
Deferred Compensation Liability, Fair Value	32.1	38
Contingent consideration and acquired contingent liabilities	23.9	34.7
Total liabilities at fair value	56	72.7
Recurring \| Level 1
Assets:
Rabbi Trust Investments, Fair Value Disclosure	23.1	23.5
Other Assets, Fair Value Disclosure	39.5	31.1
Assets, Fair Value Disclosure	62.6	54.6
Liabilities:
Deferred Compensation Liability, Fair Value	0	0
Contingent consideration and acquired contingent liabilities	0	0
Total liabilities at fair value	0	0
Recurring \| Level 2
Assets:
Rabbi Trust Investments, Fair Value Disclosure	9.8	9.5
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	9.8	9.5
Liabilities:
Deferred Compensation Liability, Fair Value	32.1	38
Contingent consideration and acquired contingent liabilities	0	0
Total liabilities at fair value	32.1	38
Recurring \| Level 3
Assets:
Rabbi Trust Investments, Fair Value Disclosure	0	0
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Liabilities:
Deferred Compensation Liability, Fair Value	0	0
Contingent consideration and acquired contingent liabilities	23.9	34.7
Total liabilities at fair value	$ 23.9	$ 34.7

Financial Instruments and Fai_5

Financial Instruments and Fair Value Measurements (Schedule of Reconciliation of Changes in Fair Value of Contingent Liabilities) (Details) - Level 3 - Recurring - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2021	Dec. 25, 2020
Contingent Liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 34.7
Fair value adjustment	(10.8)
Ending balance	23.9
StrataGraft [Member] \| Stratatech
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of contingent liability	23.9	$ 19.1
MNK-6105 [Member] \| Ocera [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Contingent Consideration, Liability	$ 0	$ 15.6

Financial Instruments and Fai_6

Financial Instruments and Fair Value Measurements (Schedule of Carrying Amount and Fair Value of Long-term Debt) (Details) - USD ($) $ in Millions	Mar. 26, 2021	Dec. 25, 2020	Oct. 11, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term Debt, Current Maturities	$ 1,717.9	$ 3,622.6
Total debt, fair value	4,574.3	3,944.3
Long-term Debt	0	0
Total Debt	5,164.4	5,283.3
Unsecured Debt	1,660.7	1,660.7
Secured Debt	3,503.7	3,622.6
9.50% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	4.2	4.2
Unsecured Debt	10.4	10.4
5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	407.7	191.2
Unsecured Debt	610.3	610.3
8.00% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	1.3	1.3
Unsecured Debt	4.4	4.4
4.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	26.2	11.1
Unsecured Debt	133.7	133.7
5.625% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	337.1	158.9
Unsecured Debt	514.7	514.7
Term Loan due 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Secured Debt	1,411.2	1,505.2
5.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	258.1	115.4
Unsecured Debt	387.2	387.2
10.00% Second Lien Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	321.8	279
Secured Debt	322.9	322.9
Term Loan due 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	369.8	367.9
Secured Debt	374.6	399.5
10.00% First Lien Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	553.4	528.4
Secured Debt	495	495
2017 Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	900	900
Secured Debt	900	900
Term Loan due Sept 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Total debt, fair value	1,394.7	1,386.9
Secured Debt	$ 1,411.2	$ 1,505.2
Unsecured Debt \| 5.625% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.625%
Senior Notes \| 5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.75%
Senior Notes \| 4.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Senior Notes \| 5.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.50%
Senior Notes \| 10.00% Second Lien Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage			10.00%
Debentures \| 9.50% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	9.50%
Debentures \| 8.00% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	8.00%
Level 1 \| Unsecured Debt \| 5.625% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.625%
Level 1 \| Senior Notes \| 4.88% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	4.875%
Level 1 \| Senior Notes \| 5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.75%
Level 1 \| Senior Notes \| 4.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Level 1 \| Senior Notes \| 5.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	5.50%
Level 1 \| Senior Notes \| 10.00% Second Lien Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	10.00%
Level 2 \| Debentures \| 9.50% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	9.50%
Level 2 \| Debentures \| 8.00% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt Instrument, Interest Rate, Stated Percentage	8.00%

Financial Instruments and Fai_7

Financial Instruments and Fair Value Measurements (Schedules of Concentration of Risk) (Details)	3 Months Ended		12 Months Ended
	Mar. 26, 2021	Mar. 27, 2020	Dec. 25, 2020
Distributor Concentration Risk \| Revenue from Contract with Customer Benchmark [Member] \| CuraScript, Inc
Concentration Risk
Concentration Risk, Percentage	24.90%	24.60%
Distributor Concentration Risk \| Accounts Receivable Attributable to Distributors \| Amerisource Bergen Corporation [Member]
Concentration Risk
Concentration Risk, Percentage	33.20%		33.60%
Distributor Concentration Risk \| Accounts Receivable Attributable to Distributors \| McKesson Corporation [Member]
Concentration Risk
Concentration Risk, Percentage	15.90%		18.20%
Distributor Concentration Risk \| Accounts Receivable Attributable to Distributors \| CuraScript, Inc
Concentration Risk
Concentration Risk, Percentage	11.10%
Product Concentration Risk \| Net Sales Attributable to Products \| Acthar
Concentration Risk
Concentration Risk, Percentage	23.10%	25.20%
Product Concentration Risk \| Net Sales Attributable to Products \| Inomax
Concentration Risk
Concentration Risk, Percentage	24.00%	21.30%
Product Concentration Risk \| Net Sales Attributable to Products \| Ofirmev
Concentration Risk
Concentration Risk, Percentage		11.20%
Product Concentration Risk \| Net Sales Attributable to Products \| Therakos [Member]
Concentration Risk
Concentration Risk, Percentage	12.00%

Segment Data (Schedule of Segme

Segment Data (Schedule of Segment Reporting Information by Business Segment) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 26, 2021	Mar. 27, 2020
Net sales		$ 558	$ 665.8
Operating Income (Loss)		(17.5)	(6.3)
Depreciation and amortization		(145.3)	(197.6)
Employee Benefits and Share-based Compensation		(3.6)	(6.7)
Opioid-related litigation settlement gain (Note 11)		0	(16.8)
Non-restructuring impairment charges		(64.5)	0
Specialty Brands
Net sales		408.4	490.6
Operating Income (Loss)		212.1	220.5
Specialty Generics
Net sales		149.6	175.2
Operating Income (Loss)		31.7	63.2
Corporate, Non-Segment
Corporate and unallocated expenses	[1]	(22.6)	(57.5)
Depreciation and amortization		(169.6)	(223.1)
Restructuring and related charges, net		(0.4)	1.8
Separation Costs	[2]	(0.6)	(21.3)
Opioid-related litigation settlement gain (Note 11)	[3]	0	16.8
Operating Segments
Operating Income (Loss)		$ 243.8	$ 283.7

[1]	Includes administration expenses and certain compensation, legal, environmental and other costs not charged to the Company's reportable segments.
[2]	Represents costs included in SG&A expenses, primarily related to professional fees and costs incurred in preparation for the Chapter 11 proceedings. As of the Petition Date, professional fees directly related to the Chapter 11 proceedings that were previously reflected as separation costs are being classified on a go-forward basis as reorganization items, net.
[3]	Represents the change in the Settlement Warrants' fair value. Refer to Note 11 for further information.

Segment Data (Schedule of Net S

Segment Data (Schedule of Net Sales from External Customers by Products) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 26, 2021		Mar. 27, 2020
Segment Reporting Information
Net sales		$ 558		$ 665.8
Medicaid Lawsuit [Member]
Segment Reporting Information
Decrease in revenue		12.5
Specialty Generics
Segment Reporting Information
Net sales		149.6		175.2
Specialty Brands
Segment Reporting Information
Net sales		408.4		490.6
Acthar \| Specialty Brands
Segment Reporting Information
Net sales		129	[1]	167.6
Inomax \| Specialty Brands
Segment Reporting Information
Net sales		134		141.7
Ofirmev \| Specialty Brands
Segment Reporting Information
Net sales		12.8		74.9
Therakos immunotherapy \| Specialty Brands
Segment Reporting Information
Net sales		66.8		63.7
Amitiza [Member] \| Specialty Brands
Segment Reporting Information
Net sales	[2]	61.4		41.1
Other \| Specialty Generics
Segment Reporting Information
Net sales		5.5		4.1
Other \| Specialty Brands
Segment Reporting Information
Net sales		4.4		1.6
Hydrocodone (API) [Member] \| Specialty Generics
Segment Reporting Information
Net sales		23.3		26.5
Oxycodone (API) [Member] \| Specialty Generics
Segment Reporting Information
Net sales		17.2		16.9
Acetaminophen (API) [Member] \| Specialty Generics
Segment Reporting Information
Net sales		45.5		44.1
Other Controlled Substances [Member] \| Specialty Generics
Segment Reporting Information
Net sales		$ 58.1		$ 83.6

[1]	The three months ended March 26, 2021 includes the prospective change to the Medicaid rebate calculation that began in June 2020, which impacted Acthar Gel net sales by $12.5 million. See Note 11 for further detail on the status of the Medicaid lawsuit.
[2]	Amitiza consists of both product net sales and royalties. Refer to Note 2 for further details on Amitiza's revenues.