DexCom (DXCM) 10-Q25 Apr 242024 Q1 Quarterly reportFinancial data

Company Profile

Cover

Cover - shares	3 Months Ended
Cover - shares	Mar. 31, 2024	Apr. 18, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	000-51222
Entity Registrant Name	DEXCOM, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0857544
Entity Address, Address Line One	6340 Sequence Drive
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	200-0200
Title of 12(b) Security	Common Stock, $0.001 Par Value Per Share
Trading Symbol	DXCM
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		397,683,837
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001093557
Current Fiscal Year End Date	--12-31

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 851.2	$ 566.3
Short-term marketable securities	2,045.8	2,157.8
Accounts receivable, net	978.6	973.9
Inventory	589.1	559.6
Prepaid and other current assets	156	168.3
Total current assets	4,620.7	4,425.9
Property and equipment, net	1,108.6	1,113.1
Operating lease right-of-use assets	68	71.4
Goodwill	23.2	25.2
Intangibles, net	123.3	134.5
Deferred tax assets	460.7	419.4
Other assets	77.7	75
Total assets	6,482.2	6,264.5
Current liabilities:
Accounts payable and accrued liabilities	1,446.6	1,345.5
Accrued payroll and related expenses	110.5	171
Short-term operating lease liabilities	20.7	21.1
Deferred revenue	16.4	18.4
Total current liabilities	1,594.2	1,556
Long-term senior convertible notes	2,436	2,434.2
Long-term operating lease liabilities	75.8	80.1
Other long-term liabilities	129.4	125.6
Total liabilities	4,235.4	4,195.9
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value, 5.0 million shares authorized; no shares issued and outstanding at March 31, 2024 and December 31, 2023	0	0
Common stock, $0.001 par value, 800.0 million shares authorized; 408.5 million and 396.1 million shares issued and outstanding, respectively, at March 31, 2024; and 407.2 million and 385.4 million shares issued and outstanding, respectively, at December 31, 2023	0.4	0.4
Additional paid-in capital	2,510.6	3,514.6
Accumulated other comprehensive loss	(37.3)	(16.7)
Retained earnings	1,167.8	1,021.4
Treasury stock, at cost; 12.4 million shares at March 31, 2024 and 21.8 million shares at December 31, 2023	(1,394.7)	(2,451.1)
Total stockholders’ equity	2,246.8	2,068.6
Total liabilities and stockholders’ equity	$ 6,482.2	$ 6,264.5

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share)	$ 0.001	$ 0.001
Preferred stock authorized (in shares)	5,000,000	5,000,000
Preferred stock issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.001	$ 0.001
Common stock authorized (in shares)	800,000,000	800,000,000
Common stock issued (in shares)	408,500,000	407,200,000
Common stock outstanding (in shares)	396,100,000	385,400,000
Treasury stock (in shares)	12,400,000	21,800,000

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Revenue	$ 921	$ 741.5
Cost of sales	359.1	278.9
Gross profit	561.9	462.6
Operating expenses:
Research and development	141.5	119
Selling, general and administrative	319.3	296.4
Total operating expenses	460.8	415.4
Operating income	101.1	47.2
Other income (expense), net	31.4	17.3
Income before income taxes	132.5	64.5
Income tax expense (benefit)	(13.9)	15.9
Net income	$ 146.4	$ 48.6
Basic net income per share (in USD per share)	$ 0.38	$ 0.13
Shares used to compute basic net income per share (in shares)	390.2	386.7
Diluted net income per share (in USD per share)	$ 0.36	$ 0.12
Shares used to compute diluted net income per share (in shares)	416.7	418.5

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 146.4	$ 48.6
Other comprehensive income (loss), net of tax:
Translation adjustments and other	(19.2)	1.4
Unrealized gain (loss) on marketable debt securities	(1.4)	3.7
Total other comprehensive income (loss), net of tax	(20.6)	5.1
Comprehensive income	$ 125.8	$ 53.7

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Treasury Stock
Balance at beginning of period (in shares) at Dec. 31, 2022		386.3
Balance at beginning of period at Dec. 31, 2022	$ 2,131.8	$ 0.4	$ 2,258.1	$ (11.6)	$ 479.9	$ (595)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under equity incentive plans (in shares)		1.1
Issuance of common stock for Employee Stock Purchase Plan (in shares)		0.2
Issuance of common stock for Employee Stock Purchase Plan	12.3		12.3
Share-based compensation expense	35.2		35.2
Net income	48.6				48.6
Other comprehensive income (loss), net of tax	5.1			5.1
Balance at end of period (in shares) at Mar. 31, 2023		387.6
Balance at end of period at Mar. 31, 2023	$ 2,233	$ 0.4	2,305.6	(6.5)	528.5	(595)
Balance at beginning of period (in shares) at Dec. 31, 2023	385.4	385.4
Balance at beginning of period at Dec. 31, 2023	$ 2,068.6	$ 0.4	3,514.6	(16.7)	1,021.4	(2,451.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under equity incentive plans (in shares)		1.2
Issuance of common stock for Employee Stock Purchase Plan (in shares)		0.1
Issuance of common stock for Employee Stock Purchase Plan	13.4		13.4
Issuance of common stock in connection with achievement of regulatory approval milestone, net of issuance costs (in shares)		1.5
Issuance of common stock in connection with achievement of sales-based milestone, net of issuance costs	0		(188.1)			188.1
Exercise and settlement of warrants (in shares)		7.9
Exercise and settlement of warrants	0		(868.3)			868.3
Share-based compensation expense	39		39
Net income	146.4				146.4
Other comprehensive income (loss), net of tax	$ (20.6)			(20.6)
Balance at end of period (in shares) at Mar. 31, 2024	396.1	396.1
Balance at end of period at Mar. 31, 2024	$ 2,246.8	$ 0.4	$ 2,510.6	$ (37.3)	$ 1,167.8	$ (1,394.7)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating activities
Net income	$ 146.4	$ 48.6
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	52.5	41.6
Share-based compensation	39	35.2
Non-cash interest expense	1.9	1.5
Deferred income taxes	(41.8)	(9.3)
Other non-cash income and expenses	(7.8)	(13.7)
Changes in operating assets and liabilities:
Accounts receivable, net	(5.8)	76.6
Inventory	(36.7)	(59.6)
Prepaid and other assets	11.4	(13.4)
Operating lease right-of-use assets and liabilities, net	(2)	(0.7)
Accounts payable and accrued liabilities	109.6	86.7
Accrued payroll and related expenses	(60.7)	(39.3)
Deferred revenue and other liabilities	3.2	1.2
Net cash provided by operating activities	209.2	155.4
Investing activities
Purchases of marketable securities	(992.4)	(809.6)
Proceeds from sale and maturity of marketable securities	1,121.8	697.6
Purchases of property and equipment	(56.9)	(74.7)
Other investing activities	2.3	0
Net cash provided by (used in) investing activities	74.8	(186.7)
Financing activities
Net proceeds from issuance of common stock	13.4	12.3
Other financing activities	(8.7)	(1.1)
Net cash provided by financing activities	4.7	11.2
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(3.8)	1.1
Increase (decrease) in cash, cash equivalents and restricted cash	284.9	(19)
Cash, cash equivalents and restricted cash, beginning of period	567.5	643.3
Cash, cash equivalents and restricted cash, end of period	852.4	624.3
Reconciliation of cash, cash equivalents and restricted cash, end of period:
Cash and cash equivalents	851.2	623.2
Restricted cash	1.2	1.1
Total cash, cash equivalents and restricted cash	852.4	624.3
Supplemental disclosure of non-cash investing and financing transactions:
Acquisition of property and equipment included in accounts payable and accrued liabilities	40.7	55.8
Right-of-use assets obtained in exchange for operating lease liabilities	1.1	1.9
Right-of-use assets obtained in exchange for finance lease liabilities	$ 7.4	$ 1

Organization and Significant Ac

Organization and Significant Accounting Policies	3 Months Ended
Organization and Significant Accounting Policies	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Significant Accounting Policies	1. Organization and Significant Accounting Policies Organization and Business We are a medical device company primarily focused on the design, development and commercialization of continuous glucose monitoring, or CGM, systems for the management of diabetes by patients, caregivers, and clinicians around the world. Unless the context requires otherwise, the terms “we,” “us,” “our,” the “company,” or “Dexcom” refer to DexCom, Inc. and its subsidiaries. Basis of Presentation and Principles of Consolidation We have prepared the accompanying unaudited consolidated financial statements in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Securities and Exchange Commission, or SEC, Regulation S-X. Accordingly, they do not include all of the information and disclosures required by GAAP for complete financial statements. In the opinion of management, all adjustments, which include only normal recurring adjustments considered necessary for a fair presentation, have been included. Operating results for the three months ended March 31, 2024 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2024. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes thereto for the fiscal year ended December 31, 2023 included in the Annual Report on Form 10-K that we filed with the SEC on February 8, 2024. These consolidated financial statements include the accounts of DexCom, Inc. and our wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. We have reclassified certain amounts previously reported in our financial statements to conform to the current presentation. We determine the functional currencies of our international subsidiaries by reviewing the environment where each subsidiary primarily generates and expends cash. For international subsidiaries whose functional currencies are the local currencies, we translate the financial statements into U.S. dollars using period-end exchange rates for assets and liabilities and average exchange rates for each period for revenue, costs and expenses. We include translation-related adjustments in comprehensive income and in accumulated other comprehensive loss in the equity section of our consolidated balance sheets. We record gains and losses resulting from transactions with customers and vendors that are denominated in currencies other than the functional currency and from certain intercompany transactions in other income (expense), net in our consolidated statements of operations. Significant Accounting Policies There were no material changes to our significant accounting policies as described in Note 1 “ Organization and Significant Accounting Policies Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires us to make certain estimates and assumptions that affect the amounts reported in our consolidated financial statements and the disclosures made in the accompanying notes. Areas requiring significant estimates include rebates, excess or obsolete inventories and the valuation of inventory, accruals for litigation contingencies, and the amount of our worldwide tax provision and the realizability of deferred tax assets. Despite our intention to establish accurate estimates and use reasonable assumptions, actual results may differ from our estimates. Concentration of Credit Risk Financial instruments which potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, short-term marketable securities, and accounts receivable. We limit our exposure to credit risk by placing our cash and investments with a few major financial institutions. We have also established guidelines regarding diversification of our investments and their maturities that are designed to maintain principal and maximize liquidity. We review these guidelines periodically and modify them to take advantage of trends in yields and interest rates and changes in our operations and financial position. Contract Balances Contract balances represent amounts presented in our consolidated balance sheets when either we have transferred goods or services to the customer or the customer has paid consideration to us under the contract. These contract balances include accounts receivable and deferred revenue. Payment terms vary by contract type and type of customer and generally range from 30 to 90 days. Accounts receivable as of March 31, 2024 included unbilled accounts receivable of $10.1 million. We expect to invoice and collect all unbilled accounts receivable within twelve months. We record deferred revenue when we have entered into a contract with a customer and cash payments are received or due prior to transfer of control or satisfaction of the related performance obligation. Our performance obligations are generally satisfied within twelve months of the initial contract date. The deferred revenue balances related to performance obligations that will be satisfied after twelve months were $7.4 million as of March 31, 2024 and December 31, 2023. These balances are included in other long-term liabilities in our consolidated balance sheets. Revenue recognized in the period from performance obligations satisfied in previous periods was not material for the periods presented. Net Income Per Share Basic net income per share attributable to common stockholders is calculated by dividing the net income attributable to common stockholders by the weighted-average number of common shares outstanding during the period. Diluted net income per share is computed using the weighted average number of common shares outstanding during the period and, when dilutive, potential common share equivalents. Potentially dilutive common shares consist of shares issuable from restricted stock units, or RSUs, performance stock units, or PSUs, warrants, our senior convertible notes, and collaborative sales-based milestones. Potentially dilutive common shares issuable upon vesting of RSUs, PSUs, and exercise of warrants are determined using the average share price for each period under the treasury stock method. Potentially dilutive common shares issuable upon conversion of our senior convertible notes are determined using the if-converted method. In periods of net losses, we exclude all potentially dilutive common shares from the computation of the diluted net loss per share for those periods as the effect would be anti-dilutive. The following table sets forth the computation of basic and diluted net income per share for the periods shown: Three Months Ended (In millions, except per share data) 2024 2023 Net income $ 146.4 $ 48.6 Add back interest expense, net of tax attributable to assumed conversion of senior convertible notes 2.9 1.6 Net income - diluted $ 149.3 $ 50.2 Net income per common share Basic $ 0.38 $ 0.13 Diluted $ 0.36 $ 0.12 Basic weighted average shares outstanding 390.2 386.7 Dilutive potential securities: Collaborative sales-based milestones 0.7 — RSUs and PSUs 1.3 1.3 Senior convertible notes 15.7 18.9 Warrants 8.8 11.6 Diluted weighted average shares outstanding 416.7 418.5 Outstanding anti-dilutive securities not included in the calculations of diluted net income per share attributable to common stockholders were as follows: Three Months Ended (In millions) 2024 2023 RSUs and PSUs 0.4 0.1 Senior convertible notes — 8.0 Total 0.4 8.1 Recent Accounting Guidance Recently Issued Accounting Pronouncements In November 2023, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . The ASU expands public entities’ segment disclosures by requiring disclosure of significant segment expenses that are regularly reviewed by the chief operating decision maker, or CODM, and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items, and interim disclosures of a reportable segment’s profit or loss and assets. The ASU also allows, in addition to the measure that is most consistent with U.S. GAAP, the disclosure of additional measures of segment profit or loss that are used by the CODM in assessing segment performance and deciding how to allocate resources. All disclosure requirements under ASU 2023-07 are also required for public entities with a single reportable segment. The ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, on a retrospective basis, with early adoption permitted. We are currently evaluating the impact of this standard on our disclosures. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures . The ASU requires greater disaggregation of information about a reporting entity's effective tax rate reconciliation as well as information on income taxes paid. The ASU applies to all entities subject to income taxes and is intended to help investors better understand an entity’s exposure to potential changes in jurisdictional tax legislation and assess income tax information that affects cash flow forecasts and capital allocation decisions. The ASU is effective for annual periods beginning after December 15, 2024, with early adoption permitted. The ASU should be applied on a prospective basis although retrospective application is permitted. We are currently evaluating the impact of this standard on our disclosures. On March 6, 2024, the SEC adopted SEC Release Nos. 33-11275; 34-99678, The Enhancement and Standardization of Climate-Related Disclosures for Investor, to require the disclosure of certain climate-related information in registration statements and annual reports, including Scope 1 and 2 emissions and information about climate-related risks that have materially impacted, or are reasonably likely to have a material impact on, a company’s business strategy, results of operations, or financial condition. In addition, under the final rules, certain disclosures related to severe weather events and other natural conditions will be required in audited financial statements. The disclosure requirements will begin phasing in for our reports and registration statements including financial information in the fiscal year ending December 31, 2025. On April 4, 2024, the SEC issued an order staying the final rules until the completion of judicial review. We are currently evaluating the impact of this final rule on our disclosures.

Development and Other Agreement

Development and Other Agreements	3 Months Ended
Development and Other Agreements	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Development and Other Agreements	2. Development and Other Agreements Collaboration with Verily Life Sciences On November 20, 2018, we entered into an Amended and Restated Collaboration and License Agreement with Verily Life Sciences LLC (an Alphabet Company) and Verily Ireland Limited (collectively, “Verily”), which we refer to as the Restated Collaboration Agreement. This replaced our original Collaboration and License Agreement with Verily dated August 10, 2015, as amended in October 2016, including the royalty obligations provisions under that original agreement. Pursuant to the Restated Collaboration Agreement, we and Verily agreed to jointly develop a certain next-generation CGM product, and potentially additional CGM products, for which we will have exclusive commercialization rights. The Restated Collaboration Agreement also provides us with an exclusive license to use intellectual property of Verily resulting from the collaboration, and certain Verily patents, in the development, manufacture and commercialization of blood-based or interstitial glucose monitoring products more generally (subject to certain exclusions, which are outside of the CGM field as it is commonly understood). It also provides us with non-exclusive license rights under Verily’s other intellectual property rights to develop, manufacture and commercialize those kinds of glucose monitoring products and certain CGM-product companion software functionalities. In connection with the Restated Collaboration Agreement, we developed, launched and commercialized a CGM product in connection with the collaboration. In consideration of Verily’s performance of its obligations under the joint development plan of the Restated Collaboration Agreement, the licenses granted to us and the amendment of the original agreement, we made upfront, incentive, and the product regulatory approval payments, and payments for contingent sales-based milestones upon the achievement of certain revenue targets. We account for the contingent milestones payable in shares of our common stock as equity instruments within the scope of ASC Topic 718. The product regulatory approval and sales-based milestones are accounted for as performance-based awards that vest when the performance conditions have been achieved and are recognized when the achievement of the respective contingent milestone is deemed probable. The value of the contingent milestones is based on our closing stock price on December 28, 2018, which was $29.57 per share. Upfront and Incentive payments In the fourth quarter of 2018, we made an initial payment for an upfront fee of $250.0 million through the issuance of 7.4 million shares of our common stock. We recorded a $217.7 million charge in our consolidated statements of operations during 2018 relating to the issuance of this common stock because this milestone payment did not meet the capitalization criteria. The value of the charge was based on our closing stock price of $29.57 per share on December 28, 2018, the date on which we obtained the necessary regulatory approvals and represents the date the performance- based awards were issued. In 2019, we made a cash incentive payment of $3.2 million due to the completion of certain development obligations and we recorded these payments as research and development expense in our consolidated statements of operations. Contingent milestones In the fourth quarter of 2021, we determined the achievement of the regulatory approval milestone to be probable and recorded an $87.1 million research and development charge in our consolidated statements of operations. This charge is associated with in-process research and development obtained in an asset acquisition prior to regulatory approval and therefore does not have an alternative future use. In the first quarter of 2022, we received regulatory approval and issued 2.9 million shares of our common stock in connection with our achievement of the related milestone. In the fourth quarter of 2022, we received approval from the Food and Drug Administration and determined the achievement of the sales-based milestones to be probable. As such, we capitalized the full value of the sales-based milestones, $152.4 million, as an intangible asset. The sales-based milestones are contingent upon the achievement of certain revenue targets. The value of the sales-based milestones is based on: 1) 5.2 million shares of our common stock, as agreed upon in November 2018 and 2) our closing stock price on December 28, 2018 of $29.57 per share. December 28, 2018 is the date on which we obtained the necessary regulatory approvals and represents the date the performance-based awards were issued. The intangible asset will be amortized using the straight-line method over its estimated useful life of 64 months through March 2028. The related amortization expense is recognized in cost of sales in our consolidated statements of operations. In the fourth quarter of 2023, we issued 3.7 million shares of our common stock in connection with our achievement of the first sales-based milestone. In the first quarter of 2024, we issued 1.5 million shares of our common stock in connection with our achievement of the second sales-based milestone. All milestones were paid in cash or shares of our common stock, at our election.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
Fair Value Measurements	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Assets and Liabilities Measured at Fair Value on a Recurring Basis We estimate the fair value of our Level 1 financial instruments, which are in active markets, using unadjusted quoted market prices for identical instruments. We obtain the fair values for our Level 2 financial instruments, which are not in active markets, from a primary professional pricing source that uses quoted market prices for identical or comparable instruments, rather than direct observations of quoted prices in active markets. Fair values obtained from this professional pricing source can also be based on pricing models whereby all significant observable inputs, including maturity dates, issue dates, settlement dates, benchmark yields, reported trades, broker-dealer quotes, issue spreads, benchmark securities, bids, offers or other market related data, are observable or can be derived from, or corroborated by, observable market data for substantially the full term of the asset. We validate the quoted market prices provided by our primary pricing service by comparing the fair values of our Level 2 marketable securities portfolio balance provided by our primary pricing service against the fair values provided by our investment managers. The following table summarizes financial assets that we measured at fair value on a recurring basis as of March 31, 2024, classified in accordance with the fair value hierarchy: Fair Value Measurements Using (In millions) Level 1 Level 2 Level 3 Total Cash equivalents $ 519.2 $ 13.3 $ — $ 532.5 Debt securities, available-for-sale: U.S. government agencies (1) — 1,431.9 — 1,431.9 Commercial paper — 323.9 — 323.9 Corporate debt — 290.0 — 290.0 Total debt securities, available-for-sale — 2,045.8 — 2,045.8 Other assets (2) 18.3 — — 18.3 Total assets measured at fair value on a recurring basis $ 537.5 $ 2,059.1 $ — $ 2,596.6 (1) Includes debt obligations issued by U.S. government-sponsored enterprises or U.S. government agencies. (2) Includes assets which are held pursuant to a deferred compensation plan for senior management, which consist mainly of mutual funds. The following table summarizes financial assets that we measured at fair value on a recurring basis as of December 31, 2023, classified in accordance with the fair value hierarchy: Fair Value Measurements Using (In millions) Level 1 Level 2 Level 3 Total Cash equivalents $ 315.9 $ — $ — $ 315.9 Debt securities, available-for-sale: U.S. government agencies (1) — 1,612.5 — 1,612.5 Commercial paper — 184.7 — 184.7 Corporate debt — 360.6 — 360.6 Total debt securities, available-for-sale — 2,157.8 — 2,157.8 Other assets (2) 15.2 — — 15.2 Total assets measured at fair value on a recurring basis $ 331.1 $ 2,157.8 $ — $ 2,488.9 (1) Includes debt obligations issued by U.S. government-sponsored enterprises or U.S. government agencies. (2) Includes assets which are held pursuant to a deferred compensation plan for senior management, which consist mainly of mutual funds. There were no transfers into or out of Level 3 securities during the three months ended March 31, 2024 and March 31, 2023. Fair Value of Senior Convertible Notes The fair value, based on trading prices (Level 1 inputs), of our senior convertible notes were as follows as of the dates indicated: Fair Value Measurements Using Level 1 (In millions) March 31, 2024 December 31, 2023 Senior Convertible Notes due 2025 1,327.8 1,262.8 Senior Convertible Notes due 2028 1,341.0 1,281.8 Total fair value of outstanding senior convertible notes $ 2,668.8 $ 2,544.6 See Note 5 “ Debt—Senior Convertible Notes ” to the consolidated financial statements in Part I, Item I of this Quarterly Report on Form 10-Q for more information regarding the carrying values of our senior convertible notes. Foreign Currency and Derivative Financial Instruments We enter into foreign currency forward contracts to hedge monetary assets and liabilities denominated in foreign currencies. Our foreign currency forward contracts are not designated as hedging instruments. Therefore, changes in the fair values of these contracts are recognized in earnings, thereby offsetting the current earnings effect of the related foreign currency assets and liabilities. The duration of these contracts is generally one month. The derivative gains and losses are included in other income (expense), net in our consolidated statements of operations. As of March 31, 2024 and December 31, 2023, the notional amounts of outstanding foreign currency forward contracts were $80.0 million and $71.0 million, respectively. The resulting impact on our consolidated financial statements from currency hedging activities was not significant for the three months ended March 31, 2024 and March 31, 2023. Our foreign currency exposures vary but are primarily concentrated in the Australian Dollar, the British Pound, the Canadian Dollar, the Euro, and the Malaysian Ringgit. We monitor the costs and the impact of foreign currency risks upon our financial results as part of our risk management program. We do not use derivative financial instruments for speculation or trading purposes or for activities other than risk management. We do not require and are not required to pledge collateral for these financial instruments and we do not carry any master netting arrangements to mitigate the credit risk. Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis In accordance with authoritative guidance, we measure certain non-financial assets and liabilities at fair value on a non-recurring basis. These measurements are usually performed using the discounted cash flow method or cost method and Level 3 inputs. These include items such as non-financial assets and liabilities initially measured at fair value in a business combination and non-financial long-lived assets measured at fair value for an impairment assessment. In general, non-financial assets, including goodwill, intangible assets, and property and equipment, are measured at fair value when there are indicators of impairment and are recorded at fair value only when an impairment is recognized. We hold certain other investments that we do not measure at fair value on a recurring basis. The carrying values of these investments are $39.8 million as of March 31, 2024 and $38.5 million as of December 31, 2023. We include them in other assets in our consolidated balance sheets. It is impracticable for us to estimate the fair value of these investments on a recurring basis due to the fact that these entities are privately held and limited information is available. We monitor the information that becomes available from time to time and adjust the carrying values of these investments if there are identified events or changes in circumstances that have a significant effect on the fair values. There were no significant impairment losses during the three months ended March 31, 2024 and March 31, 2023.

Balance Sheet Details and Other

Balance Sheet Details and Other Financial Information	3 Months Ended
Balance Sheet Details and Other Financial Information	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Details and Other Financial Information	4. Balance Sheet Details and Other Financial Information Short-Term Marketable Securities Short-term marketable securities, consisting of available-for-sale debt securities, were as follows as of the dates indicated: March 31, 2024 (In millions) Amortized Gross Gross Estimated Debt securities, available-for-sale: U.S. government agencies (1) $ 1,432.8 $ 0.3 $ (1.2) $ 1,431.9 Commercial paper 324.1 — (0.2) 323.9 Corporate debt 290.3 0.1 (0.4) 290.0 Total debt securities, available-for-sale $ 2,047.2 $ 0.4 $ (1.8) $ 2,045.8 (1) Includes debt obligations issued by U.S. government-sponsored enterprises or U.S. government agencies. December 31, 2023 (In millions) Amortized Gross Gross Estimated Debt securities, available-for-sale: U.S. government agencies (1) $ 1,611.8 $ 1.2 $ (0.5) $ 1,612.5 Commercial paper 184.8 — (0.1) 184.7 Corporate debt 360.8 0.1 (0.3) 360.6 Total debt securities, available-for-sale $ 2,157.4 $ 1.3 $ (0.9) $ 2,157.8 (1) Includes debt obligations issued by U.S. government-sponsored enterprises or U.S. government agencies. As of March 31, 2024, the estimated market value of our short-term debt securities with contractual maturities up to 12 months and up to 18 months was $1.77 billion and $275.6 million, respectively. As of December 31, 2023, the estimated market value of our short-term debt securities with contractual maturities up to 12 months was $2.16 billion. Gross realized gains and losses on sales of our short-term debt securities for the three months ended March 31, 2024 and March 31, 2023 were not significant. We periodically review our portfolio of debt securities to determine if any investment is impaired due to credit loss or other potential valuation concerns. For debt securities where the fair value of the investment is less than the amortized cost basis, we have assessed at the individual security level for various quantitative factors including, but not limited to, the nature of the investments, changes in credit ratings, interest rate fluctuations, industry analyst reports, and the severity of impairment. Unrealized losses on available-for-sale debt securities at March 31, 2024 were primarily due to increases in interest rates, including market credit spreads, and not due to increased credit risks associated with specific securities. Accordingly, we have not recorded an allowance for credit losses. We do not intend to sell these investments and it is not more likely than not that we will be required to sell the investments before recovery of their amortized cost bases, which may be at maturity. Inventory (In millions) March 31, 2024 December 31, 2023 Raw materials $ 301.2 $ 319.5 Work-in-process 49.8 30.0 Finished goods 238.1 210.1 Total inventory $ 589.1 $ 559.6 Prepaid and Other Current Assets (In millions) March 31, 2024 December 31, 2023 Prepaid expenses $ 59.4 $ 58.7 Prepaid inventory 31.7 31.5 Deferred compensation plan assets 18.3 15.2 Income tax receivables 6.2 13.6 Other current assets 40.4 49.3 Total prepaid and other current assets $ 156.0 $ 168.3 Property and Equipment (In millions) March 31, 2024 December 31, 2023 Land and land improvements $ 43.2 $ 34.5 Building 216.1 190.5 Furniture and fixtures 36.9 36.9 Computer software and hardware 67.5 65.8 Machinery and equipment 735.1 683.3 Leasehold improvements 283.9 283.4 Construction in progress 274.9 328.1 Total cost 1,657.6 1,622.5 Less: accumulated depreciation and amortization (549.0) (509.4) Total property and equipment, net $ 1,108.6 $ 1,113.1 Other Assets (In millions) March 31, 2024 December 31, 2023 Long-term investments $ 39.8 $ 38.5 Long-term deposits 14.4 14.4 Other assets 23.5 22.1 Total other assets $ 77.7 $ 75.0 Accounts Payable and Accrued Liabilities (In millions) March 31, 2024 December 31, 2023 Accounts payable trade $ 269.7 $ 276.4 Accrued tax, audit, and legal fees 43.0 42.6 Accrued rebates 1,050.1 950.7 Accrued warranty 7.2 12.6 Income tax payable 11.9 7.5 Deferred compensation plan liabilities 18.3 15.2 Other accrued liabilities 46.4 40.5 Total accounts payable and accrued liabilities $ 1,446.6 $ 1,345.5 Accrued Payroll and Related Expenses (In millions) March 31, 2024 December 31, 2023 Accrued wages, bonus and taxes $ 81.3 $ 139.8 Other accrued employee benefits 29.2 31.2 Total accrued payroll and related expenses $ 110.5 $ 171.0 Other Long-Term Liabilities (In millions) March 31, 2024 December 31, 2023 Finance lease obligations $ 57.6 $ 58.6 Deferred revenue, long-term 7.4 7.4 Asset retirement obligation 15.9 15.7 Other tax liabilities 43.7 38.7 Other liabilities 4.8 5.2 Total other long-term liabilities $ 129.4 $ 125.6 Other Income (Expense), Net Three Months Ended (In millions) 2024 2023 Interest and dividend income $ 36.3 $ 22.3 Interest expense (4.6) (4.6) Other expense, net (0.3) (0.4) Total other income (expense), net $ 31.4 $ 17.3

Debt

Debt	3 Months Ended
Debt	Mar. 31, 2024
Debt Disclosure [Abstract]
Debt	5. Debt Senior Convertible Notes The carrying amounts of our senior convertible notes were as follows as of the dates indicated: (In millions) March 31, 2024 December 31, 2023 Principal amount: Senior Convertible Notes due 2025 1,207.5 1,207.5 Senior Convertible Notes due 2028 1,250.0 1,250.0 Total principal amount 2,457.5 2,457.5 Unamortized debt issuance costs (21.5) (23.3) Carrying amount of senior convertible notes $ 2,436.0 $ 2,434.2 For our senior convertible notes for which the if-converted value exceeded the principal amount, the amount in excess of principal was as follows as of the dates indicated: (In millions) March 31, 2024 December 31, 2023 Senior Convertible Notes due 2025 105.4 56.1 Senior Convertible Notes due 2028 103.8 33.6 Total by which the notes ’ if-converted value exceeds their principal amount $ 209.2 $ 89.7 The following table summarizes the components of interest expense and the effective interest rates for our senior convertible notes for the periods shown: Three Months Ended (In millions) 2024 2023 Cash interest expense: Contractual coupon interest (1) $ 1.9 $ 2.2 Non-cash interest expense: Amortization of debt issuance costs 1.8 1.5 Total interest expense recognized on senior notes $ 3.7 $ 3.7 Effective interest rate: Senior Convertible Notes due 2023 (2) * 1.1 % Senior Convertible Notes due 2025 0.5 % 0.5 % Senior Convertible Notes due 2028 0.7 % * (1) Interest on our unsecured senior convertible notes due 2023, or the 2023 Notes, began accruing upon issuance and was payable semi-annually on June 1 and December 1 of each year until the 2023 Notes matured on December 1, 2023. Interest on our unsecured senior convertible notes due 2025, or the 2025 Notes, began accruing upon issuance and is payable semi-annually on May 15 and November 15 of each year. Interest on our unsecured senior convertible notes due 2028, or the 2028 Notes, began accruing upon issuance and is payable semi-annually on May 15 and November 15 of each year. (2) The effective interest rate presented represents the rate applicable for the period outstanding. The 2023 Notes matured on December 1, 2023 and are no longer outstanding. * Not applicable as no notes were outstanding at this date. Convertible Debt Summary The following table summarizes the key details for the 2023 Notes, 2025 Notes, and 2028 Notes: Senior Convertible Notes Offering Completion Date Maturity Date Stated Interest Rate Aggregate Principal Amount Issued Net Proceeds (1) Initial Conversion Rate (2) (per $1,000 principal amount) Conversion Price (per share) Settlement Methods (3) 2023 Notes (4) November 2018 December 1, 2023 0.75% $850.0 million $836.6 million 24.3476 shares $41.07 Cash and/or shares 2025 Notes May 2020 November 15, 2025 0.25% $1.21 billion $1.19 billion 6.6620 shares $150.11 Cash and/or shares 2028 Notes May 2023 May 15, 2028 0.375% $1.25 billion $1.23 billion 6.1571 shares $162.41 Cash and/or shares (1) Net proceeds is calculated by deducting the initial purchasers’ discounts and estimated costs directly related to the offering from the aggregate principal amount of the applicable series of notes. (2) Subject to adjustments as defined in the applicable indentures. (3) The 2025 Notes and 2028 Notes may be settled in cash, stock, or a combination thereof, solely at our discretion. The 2023 Notes, while outstanding, could be settled in cash, stock, or a combination thereof, solely at our discretion. (4) The 2023 Notes matured on December 1, 2023 and are no longer outstanding. We use the if-converted method for assumed conversion of our senior convertible notes to compute the weighted average shares of common stock outstanding for diluted earnings per share. No principal payments are due on the senior convertible notes prior to maturity. Other than restrictions relating to certain fundamental changes and consolidations, mergers or asset sales and customary anti-dilution adjustments, the indenture relating to our senior convertible notes include customary terms and covenants, including certain events of default after which the senior convertible notes may be due and payable immediately. 2023 Note Hedge In connection with the offering of the 2023 Notes, in November 2018 we entered into convertible note hedge transactions, or the 2023 Note Hedge, with two of the initial purchasers of the 2023 Notes, which we refer to as the 2023 Counterparties, entitling us to purchase up to 20.7 million shares of our common stock. The 2023 Note Hedge expired on December 1, 2023. See below for a description of conversion activity related to the 2023 Notes and shares received as the result of exercising the remaining portion of the 2023 Note Hedge in 2023. 2023 Warrants In November 2018, we also sold warrants, or the 2023 Warrants, to the 2023 Counterparties to acquire up to 20.7 million shares of our common stock. The 2023 Warrants require net share settlement and a pro-rated number of warrants will expire on each of the 60 scheduled trading days starting on March 1, 2024. We received $183.8 million in cash proceeds from the sale of the 2023 Warrants, which we recorded in additional paid-in capital during 2018. The 2023 Warrants could have a dilutive effect on our earnings per share to the extent that the price of our common stock during a given measurement period exceeds the strike price of the 2023 Warrants. The strike price of the 2023 Warrants was initially $49.60 per share, subject to certain adjustments under the terms of the warrant agreements. We use the treasury share method for assumed conversion of the 2023 Warrants when computing the weighted average common shares outstanding for diluted earnings per share. On February 13, 2024, we entered into a warrant termination agreement with one of the 2023 Counterparties to terminate outstanding warrants to purchase an aggregate of 10.3 million shares of common stock. In consideration of the termination of these warrants, we delivered 6.0 million shares of our common stock to the holder. During the first quarter of 2024, a portion of the 2023 Warrants was exercised and we issued 1.9 million shares of our common stock in addition to the aforementioned 6.0 million shares issued in connection with the warrant termination agreement. 2028 Capped Call Transactions In May 2023, in connection with the offering of the 2028 Notes, we entered into privately negotiated capped call transactions, or the 2028 Capped Calls, with certain financial institutions. The 2028 Capped Calls cover, subject to anti-dilution adjustments substantially similar to those applicable to the 2028 Notes, the number of shares of our common stock initially underlying the 2028 Notes. The 2028 Capped Calls are expected generally to reduce potential dilution to our common stock upon conversion of the 2028 Notes and/or offset any cash payments that we are required to make in excess of the principal amount of converted 2028 Notes, as the case may be, with such reduction and/or offset subject to a cap. The 2028 Capped Calls have an initial cap price of $212.62 per share, subject to adjustments, which represents a premium of 80% over the closing price of our common stock of $118.12 per share on the Nasdaq Global Select Market on May 2, 2023. The cost to purchase the 2028 Capped Calls of $101.3 million was recorded as a reduction to additional paid-in capital in our consolidated balance sheets as the 2028 Capped Calls met the criteria for classification in stockholders’ equity. Conversion Activity for Senior Convertible Notes The 2023 Notes matured on December 1, 2023 and all outstanding principal was settled. There was no conversion activity for the 2025 Notes or 2028 Notes for the three months ended March 31, 2024 . See the following table for the details of conversion activity for the 2023 Notes for the fiscal year ended December 31, 2023: Fiscal Period Converted Notes Aggregate Principal Amount Converted Shares Issued for Settlement Shares Received from Exercise of 2023 Note Hedge 1/1/2023 - 12/31/2023 2023 Notes $774.8 million 12.2 million 12.2 million Conversion Rights for Senior Convertible Notes Holders of our outstanding senior convertible notes have the right to require us to repurchase for cash all or a portion of their notes at 100% of their principal amount, plus any accrued and unpaid interest, upon the occurrence of a fundamental change (as defined in the applicable indenture relating to the notes). We are also required to increase the conversion rate for holders who convert their notes in connection with certain fundamental changes occurring prior to the maturity date or following the delivery by Dexcom of a notice of redemption. The following table outlines the conversion options related for each of our senior convertible notes: Summary of Conversions Rights at the Option of the Holders for the 2025 Notes and 2028 Notes, which we refer to collectively as the Notes Conversion Rights at the Option of the Holders Holders of the Notes have the ability to convert all or a portion of their notes in multiples of $1,000 principal amount, at their option prior to 5:00 p.m., New York City time, on the business day immediately preceding August 15, 2025 and February 15, 2028 for the 2025 Notes and 2028 Notes, respectively, only under the following circumstances: Circumstance 1 (1) During any calendar quarter commencing after the applicable period (and only during such calendar quarter), if the last reported sale price of Dexcom’s common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the applicable conversion price for the Notes on each applicable trading day Circumstance 2 During the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of the Notes for each trading day of that five consecutive trading day period was less than 98% of the product of the last reported sale price of Dexcom’s common stock and the applicable conversion rate of the Notes on each such trading day Circumstance 3 If we call any or all of the Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date (only with respect to the notes called or deemed called for redemption) Circumstance 4 Upon the occurrence of specified corporate events Circumstance 5 (2) Holders of the Notes may convert all or a portion of their Notes regardless of the foregoing circumstances prior to the close of business on the business day immediately preceding the maturity date for the 2025 Notes and prior to the close of business on the second scheduled trading day immediately preceding the maturity date for the 2028 Notes (1) Circumstance 1 is available after the calendar quarter ended September 30, 2020 and September 30, 2023 for the 2025 Notes and 2028 Notes, respectively. (2) Circumstance 5 is available on or after August 15, 2025 and February 15, 2028 for the 2025 Notes and 2028 Notes, respectively. Summary of Conversion Right at the Option of the Company for the 2025 Notes and 2028 Notes Conversion Right at Our Option (1) Dexcom may redeem for cash all or part of the Notes, at its option, if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which Dexcom provides notice of redemption. The redemption price will be equal to 100% of the principal amount of the Notes to be redeemed plus accrued and unpaid interest to, but excluding, the redemption date (1) Dexcom does not have the right to redeem the Notes prior to May 20, 2023 and May 20, 2026 for the 2025 Notes and 2028 Notes, respectively. Dexcom has the right to redeem the notes on or after May 20, 2023 and prior to August 15, 2025 for the 2025 Notes, and on or after May 20, 2026 and prior to February 15, 2028 for the 2028 Notes. Revolving Credit Agreement Terms of the Revolving Credit Agreement In June 2023, we entered into the First Amendment to the Second Amended and Restated Credit Agreement, as amended, or the Amended Credit Agreement, which we had previously entered into in October 2021. The Amended Credit Agreement is a five-year revolving credit facility, or the Credit Facility, that provides for an available principal amount of $200.0 million which can be increased up to $500.0 million at our option subject to customary conditions and approval of our lenders. The Amended Credit Agreement will mature on October 13, 2026. Borrowings under the Amended Credit Agreement are available for general corporate purposes, including working capital and capital expenditures. Information related to availability and outstanding borrowings on our Amended Credit Agreement is as follows as of the date indicated: (In millions) March 31, 2024 Available principal amount 200.0 Letters of credit sub-facility 25.0 Outstanding borrowings — Outstanding letters of credit 7.6 Total available balance $ 192.4 Revolving loans under the Amended Credit Agreement bear interest at our choice of one of three base rates plus a range of applicable rates that are based on our leverage ratio. The minimum and maximum range of applicable rates per annum with respect to any ABR Loan, Term Benchmark Revolving Loan, or RFR Revolving Loan, each as defined in the Amended Credit Agreement under the captions “ABR Spread”, “Term Benchmark/CDOR Spread”, and “RFR Spread”, or “Unused Commitment Fee Rate”, respectively, are outlined in the following table: Range ABR Spread Term Benchmark/CDOR Spread and RFR Spread Unused Commitment Fee Rate Minimum 0.375% 1.375% 0.175% Maximum 1.000% 2.000% 0.250% Our obligations under the Amended Credit Agreement are guaranteed by our existing and future wholly-owned domestic subsidiaries, and are secured by a first-priority security interest in substantially all of the assets of Dexcom and the guarantors, including all or a portion of the equity interests of our domestic subsidiaries and first-tier foreign subsidiaries but excluding real property and intellectual property (which is subject to a negative pledge). The Amended Credit Agreement contains covenants that limit certain indebtedness, liens, investments, transactions with affiliates, dividends and other restricted payments, subordinated indebtedness and amendments to subordinated indebtedness documents, and sale and leaseback transactions of Dexcom or any of its domestic subsidiaries. The Amended Credit Agreement also requires us to maintain a maximum leverage ratio and a minimum fixed charge coverage ratio. We were in compliance with these covenants as of March 31, 2024. As of March 31, 2024, we have no other material guarantee facilities or lines of credit.

Contingencies

Contingencies	3 Months Ended
Contingencies	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Contingencies	6. Contingencies Litigation We are subject to various claims, complaints and legal actions that arise from time to time in the normal course of business, including commercial insurance, product liability, intellectual property and employment related matters. In addition, from time to time we may bring claims or initiate lawsuits against various third parties with respect to matters arising out of the ordinary course of our business, including commercial and employment related matters. Between June 2021 through the three months ended March 31, 2024, we and certain Abbott Diabetes Care, Inc. (“Abbott”) entities have served patent infringement complaints against each other in multiple jurisdictions against certain continuous glucose monitoring products of each company. Abbott’s patent infringement trial, “D1”, against Dexcom commenced in the U.S.D.C., District of Delaware in March 2024. In the lead up to trial, the U.S.D.C., District of Delaware invalidated one of Abbott’s patents on factory calibration and Abbott dropped four other patents from the litigation. The claims litigated were isolated to the inserter mechanism and the wearable seal and mount of Dexcom’s G6. On March 22, 2024, a jury returned a mixed verdict. The jury found that Dexcom infringes one patent, that Dexcom did not infringe a second patent, and that Dexcom also did not infringe a third patent, which the jury also found invalid. The jury found that any infringement was not willful. It could not reach unanimity as to a fourth patent. No determination of damages was made or awarded by the jury. Dexcom will challenge the sole finding of infringement and continue to defend itself vigorously. We analyzed the potential for a loss from this litigation in accordance with ASC 450, Contingencies. We believe it is not probable that we will have an unfavorable outcome and incur a material loss contingency due to our beliefs about our position in the case. In addition, the jury did not award damages for the one patent they believe we infringed nor can we reasonably estimate the amount of loss we would incur if we do not prevail. As a result, we have not recorded an accrual for a contingent liability. Due to uncertainty surrounding the other patent litigation procedures initiated by Dexcom and Abbott throughout multiple jurisdictions, we are unable to reasonably estimate the ultimate outcome of any of the litigation matters at this time. We intend to protect our intellectual property and defend against Abbott’s claims vigorously in all of these actions. We do not believe we are party to any other currently pending legal proceedings, the outcome of which could have a material adverse effect on our business, financial condition, or results of operations. There can be no assurance that existing or future legal proceedings arising in the ordinary course of business or otherwise will not have a material adverse effect on our business, financial condition, or results of operations.

Income Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	7. Income Taxes We estimate our annual effective tax rate to be 23.8% for the full year 2024, which differs from the U.S. federal statutory rate due to state and foreign income taxes and nondeductible executive compensation, partially offset by federal tax credits generated. Our negative effective tax rate of 10.5% for the three months ended March 31, 2024 was primarily due to income tax expense from normal, recurring operations, offset by tax benefits recognized for share-based compensation for employees, net of disallowed executive compensation, and the Verily milestone payment. The Organization for Economic Co-operation and Development has a framework to implement a global minimum corporate tax of 15% for companies with global revenues and profits above certain thresholds (referred to as Pillar 2), with certain aspects of Pillar 2 effective January 1, 2024 and other aspects effective January 1, 2025. While it is uncertain whether the United States will enact legislation to adopt Pillar 2, certain countries in which we operate have adopted legislation, and other countries in which we operate are in the process of introducing legislation to implement Pillar 2. We have assessed the impact of Pillar 2 and the impact is immaterial. In January 2024, the California Franchise Tax Board commenced an audit of our California income tax returns for the 2020 and 2021 years primarily related to our research and development tax credit carryforwards. We do not expect any significant adjustments as a result of the audit.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
Stockholders' Equity	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Share-Based Compensation Our share-based compensation expense is associated with RSUs, PSUs, and our Employee Stock Purchase Plan, or ESPP. The following table summarizes our share-based compensation expense included in our consolidated statements of operations for the periods shown: Three Months Ended (In millions) 2024 2023 Cost of sales $ 3.7 $ 3.3 Research and development 11.5 11.1 Selling, general and administrative 23.8 20.8 Total share-based compensation expense $ 39.0 $ 35.2 As of March 31, 2024, unrecognized estimated compensation costs related to RSUs and PSUs totaled $362.5 million and are expected to be recognized over a weighted-average period of approximately 2.2 years. Treasury Shares In the first quarter of 2024, we issued 7.9 million treasury shares to settle a portion of the 2023 Warrants. See Note 5 “ Debt—Senior Convertible Notes ” to the consolidated financial statements for more information. In the first quarter of 2024, we issued 1.5 million treasury shares in connection with our achievement of the second sales-based milestone under the Restated Collaboration Agreement. See Note 2 “ Development and Other Agreements—Collaboration with Verily Life Sciences ” to the consolidated financial statements for more information. Repurchased shares of our common stock are held as treasury shares until they are reissued or retired. We have not yet determined the ultimate disposition of repurchased shares and consequently we continue to hold them as treasury shares rather than retiring them. Authorization of future stock repurchase programs is subject to the final determination of our Board of Directors.

Business Segment and Geographic

Business Segment and Geographic Information	3 Months Ended
Business Segment and Geographic Information	Mar. 31, 2024
Segment Reporting [Abstract]
Business Segment and Geographic Information	9. Business Segment and Geographic Information Reportable Segments An operating segment is identified as a component of a business that has discrete financial information available and for which the CODM must decide the level of resource allocation. In addition, the guidance for segment reporting indicates certain quantitative materiality thresholds. None of the components of our business meet the definition of an operating segment. We currently consider our operations to be, and manage our business globally within, one reportable segment, which is consistent with how our President and Chief Executive Officer, who is our CODM, reviews our business, makes investment and resource allocation decisions, and assesses operating performance. Disaggregation of Revenue We disaggregate revenue by geographic region and by major sales channel. We have determined that disaggregating revenue into these categories achieves the ASC Topic 606 disclosure objectives of depicting how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. Revenue by geographic region During the three months ended March 31, 2024 and March 31, 2023, no individual country outside the United States generated revenue that represented more than 10% of our total revenue. The following table sets forth revenue by our two primary geographical markets, the United States and International, based on the geographic location to which we deliver the components, for the periods shown: Three Months Ended Three Months Ended (In millions) Amount % of Total Amount % of Total United States $ 653.2 71 % $ 526.0 71 % International 267.8 29 % 215.5 29 % Total revenue $ 921.0 100 % $ 741.5 100 % Revenue by customer sales channel We sell our CGM systems through a direct sales organization and through distribution arrangements that allow distributors to sell our products. The following table sets forth revenue by major sales channel for the periods shown: Three Months Ended Three Months Ended (In millions) Amount % of Total Amount % of Total Distributor $ 778.8 85 % $ 618.9 83 % Direct 142.2 15 % 122.6 17 % Total revenue $ 921.0 100 % $ 741.5 100 %

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Millions	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net income	$ 146.4	$ 48.6

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Trading Plans During the three months ended March 31, 2024, the following Section 16 officers and directors adopted a “Rule 10b5-1 trading arrangement” (as defined in Item 408 of Regulation S-K of the Exchange Act) intended to satisfy the affirmative defense of Rule 10b5-1(c): Name Title Action Action Date Aggregate Number of Shares to be Sold (1) Expiration Date (2) Mark G. Foletta Director Adoption (3) 3/15/2024 6,000 3/15/2025 Bridgette P. Heller Director Adoption 2/25/2024 3,352 3/21/2025 Jacob S. Leach Executive Vice President, Chief Operating Officer Adoption 3/15/2024 102,732 3/15/2025 (1) The actual number of shares sold may depend on the net shares vested as a result of tax withholding obligations, the vesting of certain PSUs, the number of shares purchased under employee stock purchase plans, one or more limit orders, as applicable, and therefore, may not be determinable at this time. (2) Each trading arrangement permitted or permits transactions through and including the date listed in the table. (3) Adopted on behalf of a trust for which Mr. Foletta serves as a trustee. Each of the Rule 10b5-1 trading arrangements disclosed in the above table was adopted in accordance with our insider trading policy. Transactions made pursuant to such trading arrangements will be disclosed publicly in Section 16 filings with the SEC in accordance with applicable securities laws, rules and regulations.
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Mark G. Foletta [Member]
Trading Arrangements, by Individual
Name	Mark G. Foletta
Title	Director
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	3/15/2024
Arrangement Duration	365 days
Aggregate Available	6,000
Bridgette P. Heller [Member]
Trading Arrangements, by Individual
Name	Bridgette P. Heller
Title	Director
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	2/25/2024
Arrangement Duration	390 days
Aggregate Available	3,352
Jacob S. Leach [Member]
Trading Arrangements, by Individual
Name	Jacob S. Leach
Title	Executive Vice President, Chief Operating Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	3/15/2024
Arrangement Duration	365 days
Aggregate Available	102,732

Organization and Significant _2

Organization and Significant Accounting Policies (Policies)	3 Months Ended
Organization and Significant Accounting Policies (Policies)	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation and Principles of Consolidation We have prepared the accompanying unaudited consolidated financial statements in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Securities and Exchange Commission, or SEC, Regulation S-X. Accordingly, they do not include all of the information and disclosures required by GAAP for complete financial statements. In the opinion of management, all adjustments, which include only normal recurring adjustments considered necessary for a fair presentation, have been included. Operating results for the three months ended March 31, 2024 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2024. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes thereto for the fiscal year ended December 31, 2023 included in the Annual Report on Form 10-K that we filed with the SEC on February 8, 2024. These consolidated financial statements include the accounts of DexCom, Inc. and our wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. We have reclassified certain amounts previously reported in our financial statements to conform to the current presentation. We determine the functional currencies of our international subsidiaries by reviewing the environment where each subsidiary primarily generates and expends cash. For international subsidiaries whose functional currencies are the local currencies, we translate the financial statements into U.S. dollars using period-end exchange rates for assets and liabilities and average exchange rates for each period for revenue, costs and expenses. We include translation-related adjustments in comprehensive income and in accumulated other comprehensive loss in the equity section of our consolidated balance sheets. We record gains and losses resulting from transactions with customers and vendors that are denominated in currencies other than the functional currency and from certain intercompany transactions in other income (expense), net in our consolidated statements of operations.
Principles of Consolidation	Basis of Presentation and Principles of Consolidation We have prepared the accompanying unaudited consolidated financial statements in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Securities and Exchange Commission, or SEC, Regulation S-X. Accordingly, they do not include all of the information and disclosures required by GAAP for complete financial statements. In the opinion of management, all adjustments, which include only normal recurring adjustments considered necessary for a fair presentation, have been included. Operating results for the three months ended March 31, 2024 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2024. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes thereto for the fiscal year ended December 31, 2023 included in the Annual Report on Form 10-K that we filed with the SEC on February 8, 2024. These consolidated financial statements include the accounts of DexCom, Inc. and our wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. We have reclassified certain amounts previously reported in our financial statements to conform to the current presentation. We determine the functional currencies of our international subsidiaries by reviewing the environment where each subsidiary primarily generates and expends cash. For international subsidiaries whose functional currencies are the local currencies, we translate the financial statements into U.S. dollars using period-end exchange rates for assets and liabilities and average exchange rates for each period for revenue, costs and expenses. We include translation-related adjustments in comprehensive income and in accumulated other comprehensive loss in the equity section of our consolidated balance sheets. We record gains and losses resulting from transactions with customers and vendors that are denominated in currencies other than the functional currency and from certain intercompany transactions in other income (expense), net in our consolidated statements of operations.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires us to make certain estimates and assumptions that affect the amounts reported in our consolidated financial statements and the disclosures made in the accompanying notes. Areas requiring significant estimates include rebates, excess or obsolete inventories and the valuation of inventory, accruals for litigation contingencies, and the amount of our worldwide tax provision and the realizability of deferred tax assets. Despite our intention to establish accurate estimates and use reasonable assumptions, actual results may differ from our estimates.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments which potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, short-term marketable securities, and accounts receivable. We limit our exposure to credit risk by placing our cash and investments with a few major financial institutions. We have also established guidelines regarding diversification of our investments and their maturities that are designed to maintain principal and maximize liquidity. We review these guidelines periodically and modify them to take advantage of trends in yields and interest rates and changes in our operations and financial position.
Contract Balances	Contract Balances Contract balances represent amounts presented in our consolidated balance sheets when either we have transferred goods or services to the customer or the customer has paid consideration to us under the contract. These contract balances include accounts receivable and deferred revenue. Payment terms vary by contract type and type of customer and generally range from 30 to 90 days. Accounts receivable as of March 31, 2024 included unbilled accounts receivable of $10.1 million. We expect to invoice and collect all unbilled accounts receivable within twelve months. We record deferred revenue when we have entered into a contract with a customer and cash payments are received or due prior to transfer of control or satisfaction of the related performance obligation. Our performance obligations are generally satisfied within twelve months of the initial contract date. The deferred revenue balances related to performance obligations that will be satisfied after twelve months were $7.4 million as of March 31, 2024 and December 31, 2023. These balances are included in other long-term liabilities in our consolidated balance sheets. Revenue recognized in the period from performance obligations satisfied in previous periods was not material for the periods presented.
Net Income Per Share	Net Income Per Share Basic net income per share attributable to common stockholders is calculated by dividing the net income attributable to common stockholders by the weighted-average number of common shares outstanding during the period. Diluted net income per share is computed using the weighted average number of common shares outstanding during the period and, when dilutive, potential common share equivalents. Potentially dilutive common shares consist of shares issuable from restricted stock units, or RSUs, performance stock units, or PSUs, warrants, our senior convertible notes, and collaborative sales-based milestones. Potentially dilutive common shares issuable upon vesting of RSUs, PSUs, and exercise of warrants are determined using the average share price for each period under the treasury stock method. Potentially dilutive common shares issuable upon conversion of our senior convertible notes are determined using the if-converted method. In periods of net losses, we exclude all potentially dilutive common shares from the computation of the diluted net loss per share for those periods as the effect would be anti-dilutive.
Recent Accounting Guidance	Recent Accounting Guidance Recently Issued Accounting Pronouncements In November 2023, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . The ASU expands public entities’ segment disclosures by requiring disclosure of significant segment expenses that are regularly reviewed by the chief operating decision maker, or CODM, and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items, and interim disclosures of a reportable segment’s profit or loss and assets. The ASU also allows, in addition to the measure that is most consistent with U.S. GAAP, the disclosure of additional measures of segment profit or loss that are used by the CODM in assessing segment performance and deciding how to allocate resources. All disclosure requirements under ASU 2023-07 are also required for public entities with a single reportable segment. The ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, on a retrospective basis, with early adoption permitted. We are currently evaluating the impact of this standard on our disclosures. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures . The ASU requires greater disaggregation of information about a reporting entity's effective tax rate reconciliation as well as information on income taxes paid. The ASU applies to all entities subject to income taxes and is intended to help investors better understand an entity’s exposure to potential changes in jurisdictional tax legislation and assess income tax information that affects cash flow forecasts and capital allocation decisions. The ASU is effective for annual periods beginning after December 15, 2024, with early adoption permitted. The ASU should be applied on a prospective basis although retrospective application is permitted. We are currently evaluating the impact of this standard on our disclosures. On March 6, 2024, the SEC adopted SEC Release Nos. 33-11275; 34-99678, The Enhancement and Standardization of Climate-Related Disclosures for Investor, to require the disclosure of certain climate-related information in registration statements and annual reports, including Scope 1 and 2 emissions and information about climate-related risks that have materially impacted, or are reasonably likely to have a material impact on, a company’s business strategy, results of operations, or financial condition. In addition, under the final rules, certain disclosures related to severe weather events and other natural conditions will be required in audited financial statements. The disclosure requirements will begin phasing in for our reports and registration statements including financial information in the fiscal year ending December 31, 2025. On April 4, 2024, the SEC issued an order staying the final rules until the completion of judicial review. We are currently evaluating the impact of this final rule on our disclosures.

Organization and Significant _3

Organization and Significant Accounting Policies (Tables)	3 Months Ended
Organization and Significant Accounting Policies (Tables)	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Basic and Diluted Net Income per Share	The following table sets forth the computation of basic and diluted net income per share for the periods shown: Three Months Ended (In millions, except per share data) 2024 2023 Net income $ 146.4 $ 48.6 Add back interest expense, net of tax attributable to assumed conversion of senior convertible notes 2.9 1.6 Net income - diluted $ 149.3 $ 50.2 Net income per common share Basic $ 0.38 $ 0.13 Diluted $ 0.36 $ 0.12 Basic weighted average shares outstanding 390.2 386.7 Dilutive potential securities: Collaborative sales-based milestones 0.7 — RSUs and PSUs 1.3 1.3 Senior convertible notes 15.7 18.9 Warrants 8.8 11.6 Diluted weighted average shares outstanding 416.7 418.5
Schedule of Outstanding Anti-dilutive Securities Excluded from Diluted Net Income per Share	Outstanding anti-dilutive securities not included in the calculations of diluted net income per share attributable to common stockholders were as follows: Three Months Ended (In millions) 2024 2023 RSUs and PSUs 0.4 0.1 Senior convertible notes — 8.0 Total 0.4 8.1

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
Fair Value Measurements (Tables)	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Schedule of Fair Value Hierarchy for Financial Assets	The following table summarizes financial assets that we measured at fair value on a recurring basis as of March 31, 2024, classified in accordance with the fair value hierarchy: Fair Value Measurements Using (In millions) Level 1 Level 2 Level 3 Total Cash equivalents $ 519.2 $ 13.3 $ — $ 532.5 Debt securities, available-for-sale: U.S. government agencies (1) — 1,431.9 — 1,431.9 Commercial paper — 323.9 — 323.9 Corporate debt — 290.0 — 290.0 Total debt securities, available-for-sale — 2,045.8 — 2,045.8 Other assets (2) 18.3 — — 18.3 Total assets measured at fair value on a recurring basis $ 537.5 $ 2,059.1 $ — $ 2,596.6 (1) Includes debt obligations issued by U.S. government-sponsored enterprises or U.S. government agencies. (2) Includes assets which are held pursuant to a deferred compensation plan for senior management, which consist mainly of mutual funds. The following table summarizes financial assets that we measured at fair value on a recurring basis as of December 31, 2023, classified in accordance with the fair value hierarchy: Fair Value Measurements Using (In millions) Level 1 Level 2 Level 3 Total Cash equivalents $ 315.9 $ — $ — $ 315.9 Debt securities, available-for-sale: U.S. government agencies (1) — 1,612.5 — 1,612.5 Commercial paper — 184.7 — 184.7 Corporate debt — 360.6 — 360.6 Total debt securities, available-for-sale — 2,157.8 — 2,157.8 Other assets (2) 15.2 — — 15.2 Total assets measured at fair value on a recurring basis $ 331.1 $ 2,157.8 $ — $ 2,488.9 (1) Includes debt obligations issued by U.S. government-sponsored enterprises or U.S. government agencies. (2) Includes assets which are held pursuant to a deferred compensation plan for senior management, which consist mainly of mutual funds.
Schedule of Estimated Fair Values of Debt Instruments	The fair value, based on trading prices (Level 1 inputs), of our senior convertible notes were as follows as of the dates indicated: Fair Value Measurements Using Level 1 (In millions) March 31, 2024 December 31, 2023 Senior Convertible Notes due 2025 1,327.8 1,262.8 Senior Convertible Notes due 2028 1,341.0 1,281.8 Total fair value of outstanding senior convertible notes $ 2,668.8 $ 2,544.6 The carrying amounts of our senior convertible notes were as follows as of the dates indicated: (In millions) March 31, 2024 December 31, 2023 Principal amount: Senior Convertible Notes due 2025 1,207.5 1,207.5 Senior Convertible Notes due 2028 1,250.0 1,250.0 Total principal amount 2,457.5 2,457.5 Unamortized debt issuance costs (21.5) (23.3) Carrying amount of senior convertible notes $ 2,436.0 $ 2,434.2

Balance Sheet Details and Oth_2

Balance Sheet Details and Other Financial Information (Tables)	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Short-Term Marketable Securities	Short-term marketable securities, consisting of available-for-sale debt securities, were as follows as of the dates indicated: March 31, 2024 (In millions) Amortized Gross Gross Estimated Debt securities, available-for-sale: U.S. government agencies (1) $ 1,432.8 $ 0.3 $ (1.2) $ 1,431.9 Commercial paper 324.1 — (0.2) 323.9 Corporate debt 290.3 0.1 (0.4) 290.0 Total debt securities, available-for-sale $ 2,047.2 $ 0.4 $ (1.8) $ 2,045.8 (1) Includes debt obligations issued by U.S. government-sponsored enterprises or U.S. government agencies. December 31, 2023 (In millions) Amortized Gross Gross Estimated Debt securities, available-for-sale: U.S. government agencies (1) $ 1,611.8 $ 1.2 $ (0.5) $ 1,612.5 Commercial paper 184.8 — (0.1) 184.7 Corporate debt 360.8 0.1 (0.3) 360.6 Total debt securities, available-for-sale $ 2,157.4 $ 1.3 $ (0.9) $ 2,157.8 (1) Includes debt obligations issued by U.S. government-sponsored enterprises or U.S. government agencies.
Schedule of Inventory	(In millions) March 31, 2024 December 31, 2023 Raw materials $ 301.2 $ 319.5 Work-in-process 49.8 30.0 Finished goods 238.1 210.1 Total inventory $ 589.1 $ 559.6
Schedule of Prepaid and Other Current Assets	(In millions) March 31, 2024 December 31, 2023 Prepaid expenses $ 59.4 $ 58.7 Prepaid inventory 31.7 31.5 Deferred compensation plan assets 18.3 15.2 Income tax receivables 6.2 13.6 Other current assets 40.4 49.3 Total prepaid and other current assets $ 156.0 $ 168.3
Schedule of Property and Equipment	(In millions) March 31, 2024 December 31, 2023 Land and land improvements $ 43.2 $ 34.5 Building 216.1 190.5 Furniture and fixtures 36.9 36.9 Computer software and hardware 67.5 65.8 Machinery and equipment 735.1 683.3 Leasehold improvements 283.9 283.4 Construction in progress 274.9 328.1 Total cost 1,657.6 1,622.5 Less: accumulated depreciation and amortization (549.0) (509.4) Total property and equipment, net $ 1,108.6 $ 1,113.1
Schedule of Other Assets	Other Assets (In millions) March 31, 2024 December 31, 2023 Long-term investments $ 39.8 $ 38.5 Long-term deposits 14.4 14.4 Other assets 23.5 22.1 Total other assets $ 77.7 $ 75.0
Schedule of Accounts Payable and Accrued Liabilities	(In millions) March 31, 2024 December 31, 2023 Accounts payable trade $ 269.7 $ 276.4 Accrued tax, audit, and legal fees 43.0 42.6 Accrued rebates 1,050.1 950.7 Accrued warranty 7.2 12.6 Income tax payable 11.9 7.5 Deferred compensation plan liabilities 18.3 15.2 Other accrued liabilities 46.4 40.5 Total accounts payable and accrued liabilities $ 1,446.6 $ 1,345.5
Schedule of Accrued Payroll and Related Expenses	(In millions) March 31, 2024 December 31, 2023 Accrued wages, bonus and taxes $ 81.3 $ 139.8 Other accrued employee benefits 29.2 31.2 Total accrued payroll and related expenses $ 110.5 $ 171.0
Schedule of Other Long-Term Liabilities	(In millions) March 31, 2024 December 31, 2023 Finance lease obligations $ 57.6 $ 58.6 Deferred revenue, long-term 7.4 7.4 Asset retirement obligation 15.9 15.7 Other tax liabilities 43.7 38.7 Other liabilities 4.8 5.2 Total other long-term liabilities $ 129.4 $ 125.6
Schedule of Other Income (Expense), Net	Three Months Ended (In millions) 2024 2023 Interest and dividend income $ 36.3 $ 22.3 Interest expense (4.6) (4.6) Other expense, net (0.3) (0.4) Total other income (expense), net $ 31.4 $ 17.3

Debt (Tables)

Debt (Tables)	3 Months Ended
Debt (Tables)	Mar. 31, 2024
Debt Disclosure [Abstract]
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments	The fair value, based on trading prices (Level 1 inputs), of our senior convertible notes were as follows as of the dates indicated: Fair Value Measurements Using Level 1 (In millions) March 31, 2024 December 31, 2023 Senior Convertible Notes due 2025 1,327.8 1,262.8 Senior Convertible Notes due 2028 1,341.0 1,281.8 Total fair value of outstanding senior convertible notes $ 2,668.8 $ 2,544.6 The carrying amounts of our senior convertible notes were as follows as of the dates indicated: (In millions) March 31, 2024 December 31, 2023 Principal amount: Senior Convertible Notes due 2025 1,207.5 1,207.5 Senior Convertible Notes due 2028 1,250.0 1,250.0 Total principal amount 2,457.5 2,457.5 Unamortized debt issuance costs (21.5) (23.3) Carrying amount of senior convertible notes $ 2,436.0 $ 2,434.2
Schedule of Converted Value of Notes	For our senior convertible notes for which the if-converted value exceeded the principal amount, the amount in excess of principal was as follows as of the dates indicated: (In millions) March 31, 2024 December 31, 2023 Senior Convertible Notes due 2025 105.4 56.1 Senior Convertible Notes due 2028 103.8 33.6 Total by which the notes ’ if-converted value exceeds their principal amount $ 209.2 $ 89.7 The following table summarizes the key details for the 2023 Notes, 2025 Notes, and 2028 Notes: Senior Convertible Notes Offering Completion Date Maturity Date Stated Interest Rate Aggregate Principal Amount Issued Net Proceeds (1) Initial Conversion Rate (2) (per $1,000 principal amount) Conversion Price (per share) Settlement Methods (3) 2023 Notes (4) November 2018 December 1, 2023 0.75% $850.0 million $836.6 million 24.3476 shares $41.07 Cash and/or shares 2025 Notes May 2020 November 15, 2025 0.25% $1.21 billion $1.19 billion 6.6620 shares $150.11 Cash and/or shares 2028 Notes May 2023 May 15, 2028 0.375% $1.25 billion $1.23 billion 6.1571 shares $162.41 Cash and/or shares (1) Net proceeds is calculated by deducting the initial purchasers’ discounts and estimated costs directly related to the offering from the aggregate principal amount of the applicable series of notes. (2) Subject to adjustments as defined in the applicable indentures. (3) The 2025 Notes and 2028 Notes may be settled in cash, stock, or a combination thereof, solely at our discretion. The 2023 Notes, while outstanding, could be settled in cash, stock, or a combination thereof, solely at our discretion. (4) The 2023 Notes matured on December 1, 2023 and are no longer outstanding.
Schedule of Components of Interest Expense and Effective Interest Rates of Senior Convertible Notes	The following table summarizes the components of interest expense and the effective interest rates for our senior convertible notes for the periods shown: Three Months Ended (In millions) 2024 2023 Cash interest expense: Contractual coupon interest (1) $ 1.9 $ 2.2 Non-cash interest expense: Amortization of debt issuance costs 1.8 1.5 Total interest expense recognized on senior notes $ 3.7 $ 3.7 Effective interest rate: Senior Convertible Notes due 2023 (2) * 1.1 % Senior Convertible Notes due 2025 0.5 % 0.5 % Senior Convertible Notes due 2028 0.7 % * (1) Interest on our unsecured senior convertible notes due 2023, or the 2023 Notes, began accruing upon issuance and was payable semi-annually on June 1 and December 1 of each year until the 2023 Notes matured on December 1, 2023. Interest on our unsecured senior convertible notes due 2025, or the 2025 Notes, began accruing upon issuance and is payable semi-annually on May 15 and November 15 of each year. Interest on our unsecured senior convertible notes due 2028, or the 2028 Notes, began accruing upon issuance and is payable semi-annually on May 15 and November 15 of each year. (2) The effective interest rate presented represents the rate applicable for the period outstanding. The 2023 Notes matured on December 1, 2023 and are no longer outstanding. * Not applicable as no notes were outstanding at this date.
Schedule of Conversion Activity For Senior Convertible Notes	There was no conversion activity for the 2025 Notes or 2028 Notes for the three months ended March 31, 2024 . See the following table for the details of conversion activity for the 2023 Notes for the fiscal year ended December 31, 2023: Fiscal Period Converted Notes Aggregate Principal Amount Converted Shares Issued for Settlement Shares Received from Exercise of 2023 Note Hedge 1/1/2023 - 12/31/2023 2023 Notes $774.8 million 12.2 million 12.2 million
Schedule of Conversions Rights at the Option	The following table outlines the conversion options related for each of our senior convertible notes: Summary of Conversions Rights at the Option of the Holders for the 2025 Notes and 2028 Notes, which we refer to collectively as the Notes Conversion Rights at the Option of the Holders Holders of the Notes have the ability to convert all or a portion of their notes in multiples of $1,000 principal amount, at their option prior to 5:00 p.m., New York City time, on the business day immediately preceding August 15, 2025 and February 15, 2028 for the 2025 Notes and 2028 Notes, respectively, only under the following circumstances: Circumstance 1 (1) During any calendar quarter commencing after the applicable period (and only during such calendar quarter), if the last reported sale price of Dexcom’s common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the applicable conversion price for the Notes on each applicable trading day Circumstance 2 During the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of the Notes for each trading day of that five consecutive trading day period was less than 98% of the product of the last reported sale price of Dexcom’s common stock and the applicable conversion rate of the Notes on each such trading day Circumstance 3 If we call any or all of the Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date (only with respect to the notes called or deemed called for redemption) Circumstance 4 Upon the occurrence of specified corporate events Circumstance 5 (2) Holders of the Notes may convert all or a portion of their Notes regardless of the foregoing circumstances prior to the close of business on the business day immediately preceding the maturity date for the 2025 Notes and prior to the close of business on the second scheduled trading day immediately preceding the maturity date for the 2028 Notes (1) Circumstance 1 is available after the calendar quarter ended September 30, 2020 and September 30, 2023 for the 2025 Notes and 2028 Notes, respectively. (2) Circumstance 5 is available on or after August 15, 2025 and February 15, 2028 for the 2025 Notes and 2028 Notes, respectively. Summary of Conversion Right at the Option of the Company for the 2025 Notes and 2028 Notes Conversion Right at Our Option (1) Dexcom may redeem for cash all or part of the Notes, at its option, if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which Dexcom provides notice of redemption. The redemption price will be equal to 100% of the principal amount of the Notes to be redeemed plus accrued and unpaid interest to, but excluding, the redemption date (1) Dexcom does not have the right to redeem the Notes prior to May 20, 2023 and May 20, 2026 for the 2025 Notes and 2028 Notes, respectively. Dexcom has the right to redeem the notes on or after May 20, 2023 and prior to August 15, 2025 for the 2025 Notes, and on or after May 20, 2026 and prior to February 15, 2028 for the 2028 Notes.
Schedule of Availability and Outstanding Borrowings on Credit Agreement	Information related to availability and outstanding borrowings on our Amended Credit Agreement is as follows as of the date indicated: (In millions) March 31, 2024 Available principal amount 200.0 Letters of credit sub-facility 25.0 Outstanding borrowings — Outstanding letters of credit 7.6 Total available balance $ 192.4 Range ABR Spread Term Benchmark/CDOR Spread and RFR Spread Unused Commitment Fee Rate Minimum 0.375% 1.375% 0.175% Maximum 1.000% 2.000% 0.250%

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
Stockholders' Equity (Tables)	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Share-Based Compensation Expense	Our share-based compensation expense is associated with RSUs, PSUs, and our Employee Stock Purchase Plan, or ESPP. The following table summarizes our share-based compensation expense included in our consolidated statements of operations for the periods shown: Three Months Ended (In millions) 2024 2023 Cost of sales $ 3.7 $ 3.3 Research and development 11.5 11.1 Selling, general and administrative 23.8 20.8 Total share-based compensation expense $ 39.0 $ 35.2

Business Segment and Geograph_2

Business Segment and Geographic Information (Tables)	3 Months Ended
Business Segment and Geographic Information (Tables)	Mar. 31, 2024
Segment Reporting [Abstract]
Schedule of Revenue from External Customers by Geographic Areas	The following table sets forth revenue by our two primary geographical markets, the United States and International, based on the geographic location to which we deliver the components, for the periods shown: Three Months Ended Three Months Ended (In millions) Amount % of Total Amount % of Total United States $ 653.2 71 % $ 526.0 71 % International 267.8 29 % 215.5 29 % Total revenue $ 921.0 100 % $ 741.5 100 %
Schedule of Disaggregation of Revenue	The following table sets forth revenue by major sales channel for the periods shown: Three Months Ended Three Months Ended (In millions) Amount % of Total Amount % of Total Distributor $ 778.8 85 % $ 618.9 83 % Direct 142.2 15 % 122.6 17 % Total revenue $ 921.0 100 % $ 741.5 100 %

Organization and Significant _4

Organization and Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Organization And Summary Of Significant Accounting Policies [Line Items]
Unbilled accounts receivable	$ 10.1
Deferred revenue, long-term	$ 7.4	$ 7.4
Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Contract payment term (in days)	30 days
Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Contract payment term (in days)	90 days

Organization and Significant _5

Organization and Significant Accounting Policies - Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income	$ 146.4	$ 48.6
Add back interest expense, net of tax attributable to assumed conversion of senior convertible notes	2.9	1.6
Net income - diluted	$ 149.3	$ 50.2
Net income per common share
Basic net income per share (in USD per share)	$ 0.38	$ 0.13
Diluted net income per share (in USD per share)	$ 0.36	$ 0.12
Basic weighted average shares outstanding (in shares)	390.2	386.7
Diluted weighted average shares outstanding (in shares)	416.7	418.5
Collaborative Sales-based Milestone
Net income per common share
Dilutive potential common stock outstanding (in shares)	0.7	0
RSUs and PSUs
Net income per common share
Dilutive potential common stock outstanding (in shares)	1.3	1.3
Senior convertible notes
Net income per common share
Dilutive potential common stock outstanding (in shares)	15.7	18.9
Warrants
Net income per common share
Dilutive potential common stock outstanding (in shares)	8.8	11.6

Organization and Significant _6

Organization and Significant Accounting Policies - Anti-dilutive Securities Excluded from Calculation of Net Income (Loss) per Share (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	0.4	8.1
RSUs and PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	0.4	0.1
Senior convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	0	8

Development and Other Agreeme_2

Development and Other Agreements (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended					12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2022	Dec. 28, 2018
Other Commitments [Line Items]
Shares issued In connection with the restated collaboration agreement			2,900,000
Verily Life Sciences \| Collaborative Arrangement
Other Commitments [Line Items]
Amortization period (in months)							64 months
Initial Payment \| Verily Life Sciences \| Collaborative Arrangement
Other Commitments [Line Items]
Closing stock price (in USD per share)								$ 29.57
Initial payment on collaborative agreement					$ 250
Issuance of common stock in connection with acquisition, shares (in shares)					7,400,000
Collaborative research and development fee				$ 87.1	$ 217.7
Milestone Payments \| Verily Life Sciences \| Collaborative Arrangement
Other Commitments [Line Items]
Collaborative research and development fee						$ 3.2
Potential future common stock issuable (in shares)								5,200,000
Sales-based milestones							$ 152.4
Issuance of common stock in connection with achievement of regulatory approval milestone, net of issuance costs (in shares)	1,500,000	3,700,000

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy for Financial Assets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Cash equivalents	$ 532.5	$ 315.9
Debt securities, available-for-sale	2,045.8	2,157.8
Other assets	18.3	15.2
Total assets measured at fair value on a recurring basis	2,596.6	2,488.9
U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	1,431.9	1,612.5
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	323.9	184.7
Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	290	360.6
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Cash equivalents	519.2	315.9
Debt securities, available-for-sale	0	0
Other assets	18.3	15.2
Total assets measured at fair value on a recurring basis	537.5	331.1
Level 1 \| U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	0	0
Level 1 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	0	0
Level 1 \| Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Cash equivalents	13.3	0
Debt securities, available-for-sale	2,045.8	2,157.8
Other assets	0	0
Total assets measured at fair value on a recurring basis	2,059.1	2,157.8
Level 2 \| U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	1,431.9	1,612.5
Level 2 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	323.9	184.7
Level 2 \| Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	290	360.6
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Cash equivalents	0	0
Debt securities, available-for-sale	0	0
Other assets	0	0
Total assets measured at fair value on a recurring basis	0	0
Level 3 \| U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	0	0
Level 3 \| Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	0	0
Level 3 \| Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Debt securities, available-for-sale	$ 0	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended
Fair Value Measurements - Narrative (Details) - USD ($)	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers into or out of Level 3 securities	$ 0	$ 0
Long-term investments	39,800,000		$ 38,500,000
Impairment losses	0	$ 0
Fair value, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term investments	39,800,000		38,500,000
Foreign exchange forward \| Designated as hedging instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount of derivative instrument	$ 80,000,000		$ 71,000,000

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Values of Debt Instruments (Details) - Senior Notes - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Fair Value Disclosures [Line Items]
Total fair value of outstanding senior convertible notes	$ 2,668.8	$ 2,544.6
Senior Convertible Notes due 2025
Fair Value Disclosures [Line Items]
Total fair value of outstanding senior convertible notes	1,327.8	1,262.8
Senior Convertible Notes due 2028
Fair Value Disclosures [Line Items]
Total fair value of outstanding senior convertible notes	$ 1,341	$ 1,281.8

Balance Sheet Details and Oth_3

Balance Sheet Details and Other Financial Information - Short-Term Marketable Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Debt securities, available-for-sale:
Amortized Cost	$ 2,047.2	$ 2,157.4
Gross Unrealized Gains	0.4	1.3
Gross Unrealized Losses	(1.8)	(0.9)
Estimated Market Value	2,045.8	2,157.8
U.S. government agencies
Debt securities, available-for-sale:
Amortized Cost	1,432.8	1,611.8
Gross Unrealized Gains	0.3	1.2
Gross Unrealized Losses	(1.2)	(0.5)
Estimated Market Value	1,431.9	1,612.5
Commercial paper
Debt securities, available-for-sale:
Amortized Cost	324.1	184.8
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(0.2)	(0.1)
Estimated Market Value	323.9	184.7
Corporate debt
Debt securities, available-for-sale:
Amortized Cost	290.3	360.8
Gross Unrealized Gains	0.1	0.1
Gross Unrealized Losses	(0.4)	(0.3)
Estimated Market Value	$ 290	$ 360.6

Balance Sheet Details and Oth_4

Balance Sheet Details and Other Financial Information - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Condensed Financial Statements, Captions [Line Items]
Available-for-sale securities current	$ 1,770		$ 2,160
Term of debt instrument (in months)		12 months
Available-for-sale securities noncurrent	$ 275.6
Minimum
Condensed Financial Statements, Captions [Line Items]
Term of debt instrument (in months)	12 months
Maximum
Condensed Financial Statements, Captions [Line Items]
Term of debt instrument (in months)	18 months

Balance Sheet Details and Oth_5

Balance Sheet Details and Other Financial Information - Inventory (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 301.2	$ 319.5
Work-in-process	49.8	30
Finished goods	238.1	210.1
Total inventory	$ 589.1	$ 559.6

Balance Sheet Details and Oth_6

Balance Sheet Details and Other Financial Information - Prepaid and Other Current Assets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Prepaid expenses	$ 59.4	$ 58.7
Prepaid inventory	31.7	31.5
Deferred compensation plan assets	18.3	15.2
Income tax receivables	6.2	13.6
Other current assets	40.4	49.3
Total prepaid and other current assets	$ 156	$ 168.3

Balance Sheet Details and Oth_7

Balance Sheet Details and Other Financial Information - Property and Equipment (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Total cost	$ 1,657.6	$ 1,622.5
Less: accumulated depreciation and amortization	(549)	(509.4)
Total property and equipment, net	1,108.6	1,113.1
Land and land improvements
Property, Plant and Equipment [Line Items]
Total cost	43.2	34.5
Building
Property, Plant and Equipment [Line Items]
Total cost	216.1	190.5
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total cost	36.9	36.9
Computer software and hardware
Property, Plant and Equipment [Line Items]
Total cost	67.5	65.8
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total cost	735.1	683.3
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total cost	283.9	283.4
Construction in progress
Property, Plant and Equipment [Line Items]
Total cost	$ 274.9	$ 328.1

Balance Sheet Details and Oth_8

Balance Sheet Details and Other Financial Information - Other Assets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Long-term investments	$ 39.8	$ 38.5
Long-term deposits	14.4	14.4
Other assets	23.5	22.1
Total other assets	$ 77.7	$ 75

Balance Sheet Details and Oth_9

Balance Sheet Details and Other Financial Information - Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Accounts Payable and Accrued Liabilities [Abstract]
Accounts payable trade	$ 269.7	$ 276.4
Accrued tax, audit, and legal fees	43	42.6
Accrued rebates	1,050.1	950.7
Accrued warranty	7.2	12.6
Income tax payable	11.9	7.5
Deferred compensation plan liabilities	18.3	15.2
Other accrued liabilities	46.4	40.5
Total accounts payable and accrued liabilities	$ 1,446.6	$ 1,345.5

Balance Sheet Details and Ot_10

Balance Sheet Details and Other Financial Information - Accrued Payroll and Related Expenses (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Employee-related Liabilities, Current [Abstract]
Accrued wages, bonus and taxes	$ 81.3	$ 139.8
Other accrued employee benefits	29.2	31.2
Total accrued payroll and related expenses	$ 110.5	$ 171

Balance Sheet Details and Ot_11

Balance Sheet Details and Other Financial Information - Other Long-Term Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Finance lease obligations	$ 57.6	$ 58.6
Deferred revenue, long-term	7.4	7.4
Asset retirement obligation	15.9	15.7
Other tax liabilities	43.7	38.7
Other liabilities	4.8	5.2
Total other long-term liabilities	$ 129.4	$ 125.6

Balance Sheet Details and Ot_12

Balance Sheet Details and Other Financial Information - Other Income (Expense), Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest and dividend income	$ 36.3	$ 22.3
Interest expense	(4.6)	(4.6)
Other expense, net	(0.3)	(0.4)
Other income (expense), net	$ 31.4	$ 17.3

Debt - Carrying Values and Esti

Debt - Carrying Values and Estimated Fair Values of Debt Instruments (Details) - Senior Notes - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	May 31, 2023	May 31, 2020
Senior Convertible Notes
Total principal amount	$ 2,457.5	$ 2,457.5
Unamortized debt issuance costs	(21.5)	(23.3)
Carrying amount of senior convertible notes	2,436	2,434.2
Senior Convertible Notes due 2025
Senior Convertible Notes
Total principal amount	1,207.5	1,207.5		$ 1,210
Senior Convertible Notes due 2028
Senior Convertible Notes
Total principal amount	$ 1,250	$ 1,250	$ 1,250

Debt - Conversion Value of Conv

Debt - Conversion Value of Convertible Notes (Details) - Senior Notes - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total by which the notes’ if-converted value exceeds their principal amount	$ 209.2	$ 89.7
Senior Convertible Notes due 2025
Debt Instrument [Line Items]
Total by which the notes’ if-converted value exceeds their principal amount	105.4	56.1
Senior Convertible Notes due 2028
Debt Instrument [Line Items]
Total by which the notes’ if-converted value exceeds their principal amount	$ 103.8	$ 33.6

Debt - Components of Interest E

Debt - Components of Interest Expense and Effective Interest Rates of Senior Convertible Notes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash interest expense:
Contractual coupon interest	$ 1.9	$ 2.2
Non-cash interest expense:
Amortization of debt issuance costs	1.8	1.5
Total interest expense recognized on senior notes	$ 3.7	$ 3.7
Senior Convertible Notes due 2023
Non-cash interest expense:
Effective interest rate (as percent)		1.10%
Senior Convertible Notes due 2025
Non-cash interest expense:
Effective interest rate (as percent)	0.50%	0.50%
Senior Convertible Notes due 2028
Non-cash interest expense:
Effective interest rate (as percent)	0.70%

Debt - Schedule of Key Details

Debt - Schedule of Key Details of Convertible Notes (Details) - Senior Notes	1 Months Ended
	May 31, 2023 USD ($) $ / shares	May 31, 2020 USD ($) $ / shares	Nov. 30, 2018 USD ($) $ / shares	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Total principal amount				$ 2,457,500,000	$ 2,457,500,000
Senior Convertible Notes due 2023
Debt Instrument [Line Items]
Interest rate on convertible notes (as percent)			0.75%
Total principal amount			$ 850,000,000
Proceeds from issuance of convertible notes, net of issuance costs			$ 836,600,000
Conversion ratio			0.0243476
Conversion price of convertible notes (in USD per share) \| $ / shares			$ 41.07
Senior Convertible Notes due 2025
Debt Instrument [Line Items]
Interest rate on convertible notes (as percent)		0.25%
Total principal amount		$ 1,210,000,000		1,207,500,000	1,207,500,000
Proceeds from issuance of convertible notes, net of issuance costs		$ 1,190,000,000
Conversion ratio		0.006662
Conversion price of convertible notes (in USD per share) \| $ / shares		$ 150.11
Senior Convertible Notes due 2028
Debt Instrument [Line Items]
Interest rate on convertible notes (as percent)	0.375%
Total principal amount	$ 1,250,000,000			$ 1,250,000,000	$ 1,250,000,000
Proceeds from issuance of convertible notes, net of issuance costs	$ 1,230,000,000
Conversion ratio	0.0061571
Conversion price of convertible notes (in USD per share) \| $ / shares	$ 162.41

Debt - 2023 Note Hedge (Details

Debt - 2023 Note Hedge (Details) shares in Millions	Nov. 30, 2018 purchaser shares
Debt Instrument [Line Items]
Number of Initial purchasers \| purchaser	2
Senior Convertible Notes due 2023 \| Designated as hedging instrument \| Senior Notes
Debt Instrument [Line Items]
Stock issued upon conversion of senior notes (in shares) \| shares	20.7

Debt - 2023 Warrants (Details)

Debt - 2023 Warrants (Details) - Senior Convertible Notes due 2023 - Senior Notes $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended	3 Months Ended
	Feb. 13, 2024 shares	Nov. 30, 2018 USD ($) d $ / shares shares	Mar. 31, 2024 shares
Debt Instrument [Line Items]
Stock counterparties to acquire with warrants purchased (in shares)	10.3	20.7
Number of trading days \| d		60
Proceeds from sale of warrants \| $		$ 183.8
Exercise price of warrants or rights (in USD per share) \| $ / shares		$ 49.60
Common Stock \| BofA Warrant Transactions
Debt Instrument [Line Items]
Exercise and settlement of warrants (in shares)			6
Common Stock \| JPM Warrant Transactions
Debt Instrument [Line Items]
Exercise and settlement of warrants (in shares)			1.9

Debt - 2028 Capped Call Transac

Debt - 2028 Capped Call Transactions (Details) - Senior Convertible Notes due 2028 - Senior Notes - USD ($) $ / shares in Units, $ in Millions		1 Months Ended
	May 02, 2023	May 31, 2023
Debt Instrument [Line Items]
Capped call, cap price (in USD per share)	$ 212.62
Sale of stock premium (as percent)	80%
Closing stock price (in USD per share)	$ 118.12
Purchases of capped call transactions		$ 101.3

Debt - Conversion Activity for

Debt - Conversion Activity for Senior Convertible Notes (Details) - Senior Convertible Notes due 2023 - Senior Notes shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) shares
Debt Instrument [Line Items]
Debt instrument, convertible principal amount settled \| $	$ 774.8
Repurchase and conversions of notes (in shares)	12.2
Shares received from Note Hedge	12.2

Debt - Conversion Rights for Se

Debt - Conversion Rights for Seniors Convertible Notes (Details) - Senior Notes - d	1 Months Ended	3 Months Ended
	Nov. 30, 2018	Mar. 31, 2024
Senior Convertible Notes due 2023
Debt Instrument [Line Items]
Holder's repurchase price percentage in event of fundamental change (as percent)		100%
Number of trading days	60
Senior Convertible Notes due 2023 \| Term one \| Minimum
Debt Instrument [Line Items]
Number of trading days		20
Proportion of applicable conversion price (as percent)		130%
Senior Convertible Notes due 2023 \| Term one \| Maximum
Debt Instrument [Line Items]
Number of trading days		30
Senior Convertible Notes due 2025
Debt Instrument [Line Items]
Proportion of conversion price (as percent)		130%
Senior Convertible Notes due 2025 \| Term one \| Minimum
Debt Instrument [Line Items]
Number of trading days		20
Senior Convertible Notes due 2025 \| Term one \| Maximum
Debt Instrument [Line Items]
Number of trading days		30
Senior Convertible Notes due 2025 \| Term two
Debt Instrument [Line Items]
Number of trading days		5
Senior Convertible Notes due 2025 \| Term two \| Maximum
Debt Instrument [Line Items]
Number of trading days		5
Proportion of applicable conversion price (as percent)		98%
Senior Convertible Notes due 2028
Debt Instrument [Line Items]
Redemption price (as percent)		100%

Debt - Revolving Credit Agreeme

Debt - Revolving Credit Agreement (Details) - USD ($)	1 Months Ended	3 Months Ended
Debt - Revolving Credit Agreement (Details) - USD ($)	Jun. 30, 2023	Mar. 31, 2023	Mar. 31, 2024
Line of Credit Facility [Line Items]
Term of debt instrument (in years)		12 months
Line of credit
Line of Credit Facility [Line Items]
Term of debt instrument (in years)	5 years
Available principal amount and letters of credit sub-facility	$ 200,000,000		$ 200,000,000
Option to increase revolving line of credit	$ 500,000,000

Debt - Availability and Outstan

Debt - Availability and Outstanding Borrowings under Credit Agreement (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Jun. 30, 2023
Line of Credit Facility [Line Items]
Total available balance	$ 192,400,000
Line of credit
Line of Credit Facility [Line Items]
Available principal amount and letters of credit sub-facility	200,000,000	$ 200,000,000
Outstanding borrowings	$ 0
Line of credit \| Minimum
Line of Credit Facility [Line Items]
Unused capacity fee (as a percent)	0.175%
Line of credit \| Minimum \| Base Rate
Line of Credit Facility [Line Items]
Interest rate on convertible notes (as percent)	0.375%
Line of credit \| Minimum \| London Interbank Offered Rate (LIBOR) 1
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.375%
Line of credit \| Maximum
Line of Credit Facility [Line Items]
Unused capacity fee (as a percent)	0.25%
Line of credit \| Maximum \| Base Rate
Line of Credit Facility [Line Items]
Interest rate on convertible notes (as percent)	1%
Line of credit \| Maximum \| London Interbank Offered Rate (LIBOR) 1
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	2%
Line of credit \| Letter of credit
Line of Credit Facility [Line Items]
Available principal amount and letters of credit sub-facility	$ 25,000,000
Outstanding letters of credit	$ 7,600,000

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended
Income Taxes (Details)	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Estimated annual effective tax rate (as percent)	23.80%
Effective tax rate (as percent)	(10.50%)

Stockholders' Equity - Share-Ba

Stockholders' Equity - Share-Based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 39	$ 35.2
Cost of sales
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	3.7	3.3
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	11.5	11.1
Selling, general and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 23.8	$ 20.8

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Milestone Payments \| Verily Life Sciences \| Collaborative Arrangement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock in connection with achievement of regulatory approval milestone, net of issuance costs (in shares)	1.5	3.7
Restricted Stock Units (RSUs) and Performance Shares \| Equity Incentive Plan 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized estimated compensation costs	$ 362.5
Unrecognized compensation costs recognized weighted average period (in years)	2 years 2 months 12 days

Business Segment and Geograph_3

Business Segment and Geographic Information - Narrative (Details)	3 Months Ended
	Mar. 31, 2024 primaryMarket segment
Segment Reporting [Abstract]
Number of reportable segments \| segment	1
Number Of primary geographic markets \| primaryMarket	2

Business Segment and Geograph_4

Business Segment and Geographic Information - Schedule of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 921	$ 741.5
Proportion of revenue (as percent)	100%	100%
Distributor
Disaggregation of Revenue [Line Items]
Total revenue	$ 778.8	$ 618.9
Proportion of revenue (as percent)	85%	83%
Direct
Disaggregation of Revenue [Line Items]
Total revenue	$ 142.2	$ 122.6
Proportion of revenue (as percent)	15%	17%
United States
Disaggregation of Revenue [Line Items]
Total revenue	$ 653.2	$ 526
Proportion of revenue (as percent)	71%	71%
International
Disaggregation of Revenue [Line Items]
Total revenue	$ 267.8	$ 215.5
Proportion of revenue (as percent)	29%	29%