John Hancock GA Senior Loan Trust N-CSRSCertified semi-annual shareholder report (management investment company)

John Hancock GA Senior Loan Trust (the fund) is a Delaware statutory trust that is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as a closed-end, non-diversified management investment company. The investment objective of the fund is to generate current income.

The fund is only offered to “accredited investors” within the meaning of Regulation D under the Securities Act of 1933 (the 1933 Act), non-U.S. investors within the meaning of Regulation S under the 1933 Act, and other investors eligible to invest in a private placement.

The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (US GAAP), which require management to make certain estimates and assumptions as of the date of the financial statements. Actual results could differ from those estimates and those differences could be significant. The fund qualifies as an investment company under Topic 946 of Accounting Standards Codification of US GAAP.

Events or transactions occurring after the end of the fiscal period through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The following summarizes the significant accounting policies of the fund:

Valuation techniques include discounted cash flow models, comparison with similar instruments for which  observable market prices exist and other valuation models. Assumptions and inputs used in valuation techniques include risk-free and benchmark interest rates, credit spreads and other inputs used in estimating discount rates. For senior loans, the fund uses valuations from independent valuation firms, which are based on models developed from recognized US GAAP valuation approaches under ASC 820. Some or all of the significant inputs into these models may be unobservable and are derived either from observable market prices or rates or are estimated based on unobservable assumptions. Valuation models that employ significant unobservable inputs require a higher degree of management judgment and estimation in the determination of fair value. Judgment and estimation are usually required for the selection of the appropriate valuation model to be used, determination of expected future cash flows on the financial instrument being valued, determination of the probability of counterparty default and prepayments and selection of appropriate discount rates.

The fund uses a three-tier hierarchy to prioritize the pricing assumptions, referred to as inputs, used in valuation techniques to measure fair value. Level 1 includes securities valued using quoted prices in active markets for identical securities. Level 2 includes securities valued using other significant observable inputs. Observable inputs may include quoted prices for similar securities, interest rates, prepayment speeds and credit risk. Prices for securities valued using these inputs are received from independent pricing vendors and brokers and are based on an evaluation of the inputs described. Level 3 includes securities valued using significant unobservable inputs when market prices are not readily available or reliable, including the Advisor’s own assumptions in determining the fair value of investments. Factors used in determining value may include market or issuer specific events or trends, changes in interest rates and credit quality. The

Senior loan investments are measured at fair value based on the present value of the expected cash flows of the loans. There are no quoted prices in active markets. Assumptions and inputs used in the valuation of senior loan investments include prepayment estimates, determination of the discount rate based on the risk-free interest rate adjusted for credit risk (including estimation of probability of default), liquidity and any other adjustments that the independent valuation firm believes that a third-party market participant would take into account in pricing a transaction. Senior loan investment valuations rely primarily on the use of significant unobservable inputs, including credit assumptions, which require significant judgment and, accordingly, are classified as Level 3.

Other debt obligations are typically valued based on the evaluated prices provided by an independent pricing vendor. Independent pricing vendors utilize matrix pricing which takes into account factors such as institutional-size trading in similar groups of securities, yield, quality, coupon rate, maturity, type of issue, trading characteristics and other market data, as well as broker supplied prices. Other debt obligations are generally classified as Level 2.

Investments in open-end mutual funds are valued at their respective net asset values each business day and are generally classified as Level 1.

The following is a summary of the values by input classification of the fund’s investments as of June 30, 2023 by major security category or type:

The following is a reconciliation of Level 3 assets for which significant unobservable inputs were used to determine fair value. There were no transfers into or out of Level 3 during the period.

A change to unobservable inputs of the fund’s Level 3 securities as of June 30, 2023 could have resulted in changes to the fair value measurement, as follows:

Due to the inherent uncertainty of determining the fair value of Level 3 investments, the fair value of the investments may differ significantly from the values that would have been used had a ready market for such securities existed and may differ materially from the values that may ultimately be received or settled. Further, such investments will generally be subject to legal and other restrictions, or otherwise will be less liquid than publicly traded instruments. If the fund is required to liquidate a portfolio investment in a forced or liquidation sale, the fund might realize significantly less than the value at which such investment will have been previously been recorded. The fund’s investments will be subject to market risk. Market risk is the potential for changes in the value due to market changes. Market risk is directly impacted by the volatility and liquidity in the markets in which the investments are traded.

The fund may be subject to greater levels of credit risk, call (or “prepayment”) risk, settlement risk and liquidity risk than funds that do not invest in senior loans. Senior loans are considered predominantly speculative with respect to an issuer’s continuing ability to make principal and interest payments, and may be more volatile than other types of securities. An economic downturn or individual corporate developments could adversely affect the market for these instruments and reduce the fund’s ability to sell these instruments at an advantageous time or price. An economic downturn would generally lead to a higher non-payment rate and a senior loan may lose significant value before a default occurs. The fund may also be subject to greater levels of liquidity risk than funds that do not invest in senior loans. In addition, the senior loans in which the fund invests may not be listed on any exchange and a secondary market for such loans may be comparatively less liquid relative to markets for other more liquid fixed income securities. Consequently, transactions in senior loans may involve greater costs than transactions in more actively traded securities. Restrictions on transfers in loan agreements, a lack of publicly-available information, irregular trading activity and wide bid/ask spreads among other factors, may, in certain circumstances, make

The fund may also enter into, or acquire participations in, delayed funding loans and revolving credit facilities, in which a bank or other lender agrees to make loans up to a maximum amount upon demand by the borrower during a specified term. These commitments may have the effect of requiring the fund to increase its investment in a company at a time when it might not be desirable to do so (including at a time when the company’s financial condition makes it unlikely that such amounts will be repaid). Delayed funding loans and revolving credit facilities are subject to credit, interest rate and liquidity risk and the risks of being a lender. Unfunded loan commitments are marked to market in accordance with the fund’s valuation policies. Any related unrealized appreciation (depreciation) on unfunded commitments is included in unaffiliated investments, at value in the Statement of assets and liabilities and change in net unrealized appreciation (depreciation) in the Statement of operations. As of June 30, 2023, the fund had the following unfunded commitments outstanding.

As of December 31, 2022, the fund had no uncertain tax positions that would require financial statement recognition, derecognition or disclosure. The fund’s federal tax returns are subject to examination by the Internal Revenue Service for a period of three years.

Such distributions, on a tax basis, are determined in conformity with income tax regulations, which may differ from US GAAP. Distributions in excess of tax basis earnings and profits, if any, are reported in the fund’s financial statements as a return of capital. The final determination of tax characteristics of the fund’s distribution will occur at the end of the year and will subsequently be reported to shareholders.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Temporary book-tax differences, if any, will reverse in a subsequent period. Book-tax differences are primarily attributable to organizational cost and distributions payable.

Under the fund’s organizational documents, its Officers and Trustees are indemnified against certain liabilities arising out of the performance of their duties to the fund. Additionally, in the normal course of business, the fund enters into contracts with service providers that contain general indemnification clauses. The fund’s maximum exposure under these arrangements is unknown, as this would involve future claims that may be made against the fund that have not yet occurred. The risk of material loss from such claims is considered remote.

Manulife Investment Management Private Markets (US) LLC (the Advisor) serves as investment advisor for the fund. The fund does not have a principal underwriter. The fund has entered into a Placement Agency Agreement with John Hancock Investment Management Distributors, LLC (the Distributor), an affiliate of the Advisor, to offer to sell shares of the fund. The Advisor and Distributor are wholly owned subsidiaries of Manulife Financial Corporation (MFC). Prior to April 20, 2023, the fund had a Placement Agency Agreement with John Hancock Distributors, LLC.

The preferred return as of the end of the applicable fiscal quarter is an amount equal to (a) 1.25% (the “preferred return rate”) multiplied by (b) the fund’s net asset value as of the beginning of the fiscal quarter, adjusted to reflect additions to the fund’s net asset value resulting from new share purchases during the fiscal quarter and reductions to the fund resulting from withdrawals by, or distributions to, shareholders during the fiscal quarter (the “preferred return base”). The performance fee will not be payable for any fiscal quarter unless losses and depreciation from prior fiscal quarters have been recovered by the fund. The performance fee is accrued monthly and paid quarterly.

Affiliates of the fund owned 100% of shares of the fund on June 30, 2023.

Purchases and sales of securities, other than short-term investments, amounted to $120,932,224 and $50,068,011, respectively, for the period ended June 30, 2023.

LIBOR (London Interbank Offered Rate) is a measure of the average interest rate at which major global banks can borrow from one another. Following allegations of rate manipulation and concerns regarding its thin liquidity, in July 2017, the U.K. Financial Conduct Authority, which regulates LIBOR, announced that it will stop encouraging banks to provide the quotations needed to sustain LIBOR. As market participants transition away from LIBOR, LIBOR’s usefulness may deteriorate and these effects could be experienced until the permanent cessation of the majority of U.S. LIBOR rates in 2023. The transition process may lead to increased volatility and illiquidity in markets that currently rely on LIBOR to determine interest rates. LIBOR’s deterioration may adversely affect the liquidity and/or market value of securities that use LIBOR as a benchmark interest rate.

The ICE Benchmark Administration Limited, the administrator of LIBOR, ceased publishing certain LIBOR maturities, including some U.S. LIBOR maturities, on December 31, 2021, and ceased publishing the remaining and most liquid U.S. LIBOR maturities on June 30, 2023 on a representative basis. The 1-, 3- and 6-month USD LIBOR maturities will continue to be published based on a synthetic methodology through September 30, 2024 and are permitted to be used in all legacy contracts except cleared derivatives. It is expected that market participants have or will transition to the use of alternative reference or benchmark rates prior to the applicable LIBOR publication cessation date. Additionally, although regulators have encouraged the development and adoption of alternative rates such as the Secured Overnight Financing Rate ([1]SOFR[1]), the future utilization of LIBOR or of any particular replacement rate remains uncertain.

The impact on the transition away from LIBOR referenced financial instruments remains uncertain. It is expected that market participants will adopt alternative rates such as SOFR or otherwise amend such financial instruments to include fallback provisions and other measures that contemplate the discontinuation of LIBOR. Uncertainty and risk remain regarding the willingness and ability of issuers and lenders to include alternative rates and revised provisions in new and existing contracts or instruments. To facilitate the transition of legacy derivatives contracts referencing LIBOR, the International Swaps and Derivatives Association, Inc. launched a protocol to incorporate fallback provisions. There are obstacles to converting certain longer term securities to a new benchmark or benchmarks and the effectiveness of one versus multiple alternative reference rates has not been determined. Certain proposed replacement rates, such as SOFR, are materially different from LIBOR, and will require changes to the applicable spreads. Furthermore, the risks associated with the conversion from LIBOR may be exacerbated if an orderly transition is not completed in a timely manner.

In March 2020, the Financial Accounting Standards Board (FASB) issued an Accounting Standards Update (ASU), ASU 2020-04, which provides optional, temporary relief with respect to the financial reporting of contracts subject to certain types of modifications due to the planned discontinuation of the LIBOR and other IBOR-based reference rates as of the end of 2021. The temporary relief provided by ASU 2020-04 is

The following information in this annual report is a summary of certain changes since December 31, 2022. This information may not reflect all of the changes that have occurred since you purchased shares of the fund.

On March 2, 2023, the Board of Trustees approved changes to the fund's principal investment strategies. In this regard, the fund's principal investment strategy disclosure has been revised to clarify that the fund may borrow money or leverage its investments for the purposes of funding investments in instances of short term liquidity needs.

The fund’s investment objective is to generate current income.

Under normal market conditions, the fund will invest at least 80% of its net assets (plus any borrowings for investment purposes) in senior loans. Senior loans include first and second lien term loans, delayed draw term loans, and revolving credit facilities. Senior loans do not include commercial mortgage loans (including subordinated real estate mezzanine financing). The fund will only invest in loans and commitments that are determined to be below investment-grade. The fund’s investment policies are based on credit quality at the time of purchase. Credit quality is determined by the Advisor. The fund may invest in loans with a maturity of up to nine years from the closing date of the loan. The Advisor typically expects to employ a buy-and-hold strategy. The fund may invest in loans either by transacting directly at the initial funding date or acquiring loans in secondary market transactions.

The fund may invest in loans secured by substantially all of the assets of the borrower and the other loan parties (subject to customary exceptions), including a pledge of the equity of the borrower and its subsidiaries.  While real property is not a primary source of collateral, occasionally mortgages are part of the collateral package if the borrower owns particularly valuable real property. The fund may also invest in subordinated debt obligations to the extent permitted by the fund’s investment restrictions.

The Advisor undertakes a comprehensive due diligence process, which includes a credit review and internal loan rating process as well as review of loan terms and collateral. The Advisor does not intend to cause the fund to borrow money or leverage its investments for the purpose of funding investments, other than in instances of short-term liquidity needs, and paying fund expenses.

An investment in the fund is subject to investment and market risks, including the possible loss of the entire principal invested.

The fund’s main risks are listed below in alphabetical order, not in order of importance.

As a result of continued political tensions and armed conflicts, including the Russian invasion of Ukraine commencing in February of 2022, the extent and ultimate result of which are unknown at this time, the United States and the EU, along with the regulatory bodies of a number of countries, have imposed economic sanctions on certain Russian corporate entities and individuals, and certain sectors of Russia's economy, which may result in, among other things, the continued devaluation of Russian currency, a downgrade in the country's credit rating, and/or a decline in the value and liquidity of Russian securities, property or interests. These sanctions could also result in the immediate freeze of Russian securities and/or funds invested in prohibited assets, impairing the ability of a fund to buy, sell, receive or deliver those securities and/or assets. These sanctions or the threat of additional sanctions could also result in Russia taking counter measures or retaliatory actions, which may further impair the value and liquidity of Russian securities. The United States and other nations or international organizations may also impose additional economic sanctions or take other actions that may adversely affect Russia-exposed issuers and companies in various sectors of the Russian economy. Any or all of these potential results could lead Russia's economy into a recession. Economic sanctions and other actions against Russian institutions, companies, and individuals resulting from the ongoing conflict may also have a substantial negative impact on other economies and securities markets both regionally and globally, as well as on companies with operations in the conflict region, the extent to which is unknown at this time. The United States and the EU have also imposed similar sanctions on Belarus for its support of Russia's invasion of Ukraine. Additional sanctions may be imposed on Belarus and other countries that support Russia. Any such sanctions could present substantially similar risks as those resulting from the sanctions imposed on Russia, including substantial negative impacts on the regional and global economies and securities markets.

A widespread health crisis such as a global pandemic could cause substantial market volatility, exchange trading suspensions and closures, and affect fund performance. For example, the coronavirus pandemic (COVID-19) has resulted and may continue to result in significant disruptions to global business activity and market volatility due to disruptions in market access, resource availability, facilities operations, imposition of tariffs, export controls, and supply chain disruptions, among others. The impact of a health crisis and other epidemics and pandemics that may arise in the future, could affect the global economy in ways that cannot necessarily be foreseen at the present time. A health crisis may exacerbate other preexisting political, social, and economic risks. Any such impact could adversely affect the fund’s performance, resulting in losses to your investment.

The fund’s proxy voting policies and procedures, as well as the fund proxy voting record for the most recent twelve month period ended June 30, are available free of charge on the Securities and Exchange Commission (SEC) website at sec.gov.
All of the fund’s holdings as of the end of the third month of every fiscal quarter are filed with the SEC on Form N-PORT within 60 days of the end of the fiscal quarter. The fund’s Form N-PORT filings are available on the SEC’s website, sec.gov.