Organization	12 Months Ended
Sep. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. ORGANIZATION PennantPark Investment Corporation was organized as a Maryland corporation in January 2007. We are a closed-end, externally managed, non-diversified investment company that has elected to be treated as a BDC under the 1940 Act. Our investment objective is to generate both current income and capital appreciation while seeking to preserve capital through debt and equity investments. We invest primarily in U.S. middle-market companies in the form of first lien secured debt, second lien secured debt, subordinated debt and, to a lesser extent, equity investments. On April 24, 2007, we closed our initial public offering. On April 14, 2022, listing and trading of the Company's common stock commenced on the New York Stock Exchange after the Company voluntarily withdrew the principal listing of its common stock from the Nasdaq Stock Market LLC effective at market close on April 13, 2022. Our common stock trades on the New York Stock Exchange under the symbol “PNNT.” We execute our investment strategy directly and through our wholly owned subsidiaries, our unconsolidated joint venture and unconsolidated limited partnership. The term “subsidiary” means entities that primarily engage in investment activities in securities or other assets and are wholly owned by us. The Company does not intend to create or acquire primary control of any entity which primarily engages in investment activities of securities or other assets other than entities wholly owned by the Company. We comply with the provisions of Section 18 of the 1940 Act governing capital structure and leverage on an aggregate basis with our subsidiaries. Our subsidiaries comply with the provisions of Section 17 of the 1940 Act related to affiliated transactions and custody. To the extent that the Company forms a subsidiary advised by an investment adviser other than the Investment Adviser, the investment adviser to such subsidiaries will comply with the provisions of the1940 Act relating to investment advisory contracts, including but not limited to, Section 15, as if it were an investment adviser to the Company under Section 2(a)(20) of the 1940 Act. We have entered into an investment management agreement, (the "Investment Management Agreement"), with PennantPark Investment Advisors, LLC (the "Investment Adviser"), an external adviser that manages our day-to-day operations. We have also entered into an administration agreement, (the "Administration Agreement"), with PennantPark Investment Administrator LLC (the "Administrator"), which provides the administrative services necessary for us to operate. PennantPark Investment, through the Administrator, also provided similar services to SBIC II under a separate administration agreement. On July 31, 2020, we and certain entities and managed accounts of the private credit investment manager of Pantheon Ventures (UK) LLP (“Pantheon”) entered into a limited liability company agreement to co-manage PSLF, a newly-formed unconsolidated joint venture. In connection with this transaction, we contributed in-kind our formerly wholly-owned subsidiary, Funding I. As a result of this transaction, Funding I became a wholly-owned subsidiary of PSLF and has been deconsolidated from our financial statements. PSLF invests primarily in middle-market and other corporate debt securities consistent with our strategy. PSLF was formed as a Delaware limited liability company. See Note 4. In April 2021, we issued $150.0 million in aggregate principal amount of our 2026 Notes at a public offering price per note of 99.4%. Interest on the 2026 Notes is paid semi-annually on May 1 and November 1 of each year, at a rate of 4.50% per year, commencing November 1, 2021. The effective interest rate is 4.62%. The 2026 Notes mature on May 1, 2026 and may be redeemed in whole or in part at our option subject to a make-whole premium if redeemed more than three months prior to maturity. The 2026 Notes are general, unsecured obligations and rank equal in right of payment with all of our existing and future senior unsecured indebtedness. The 2026 Notes are effectively subordinated to all of our existing and future secured indebtedness to the extent of the value of the assets securing such indebtedness and structurally subordinated to all existing and future indebtedness and other obligations of any of our subsidiaries, financing vehicles, or similar facilities. We do not intend to list the 2026 Notes on any securities exchange or automated dealer quotation system. In October 2021, we issued $165.0 million in aggregate principal amount of our 2026 Notes-2 at a public offering price per note of 99.4%. Interest on the 2026 Notes is paid semi-annually on May 1 and November 1 of each year, at a rate of 4.00% per year, commencing May 1, 2022. The effective interest rate is 4.12%. The 2026 Notes-2 mature on November 1, 2026 and may be redeemed in whole or in part at our option subject to a make-whole premium if redeemed more than three months prior to maturity. The 2026 Notes-2 are general, unsecured obligations and rank equal in right of payment with all of our existing and future senior unsecured indebtedness. The 2026 Notes-2 are effectively subordinated to all of our existing and future secured indebtedness to the extent of the value of the assets securing such indebtedness and structurally subordinated to all existing and future indebtedness and other obligations of any of our subsidiaries, financing vehicles, or similar facilities. We do not intend to list the 2026 Notes-2 on any securities exchange or automated dealer quotation system. On November 22, 2021, we formed PNNT Investment Holdings II, LLC, a Delaware limited liability company (“Holdings II”), as a wholly owned subsidiary. On December 31, 2022, we contributed 100% of our interests in PNNT Investment Holdings, LLC (“Holdings”) to Holdings II . Effective as of January 1, 2024, Holdings II made an election to be treated as a corporation for U.S. federal income tax purposes. On January 3, 2024, we purchased an equity interest in Holdings from Holdings II and Holdings became a partnership for U.S. federal income tax purposes. The Company and Holdings II entered into a limited liability company agreement with respect to Holdings that provides for certain payments and the sharing of income, gain, loss and deductions attributable to Holdings’ investments. In January 2022, we funded PennantPark-TSO Senior Loan Fund II LP, ("PTSF II"), an unconsolidated limited partnership, organized as a Delaware limited liability partnership. We sold $82.3 million in investments to a wholly-owned subsidiary of PTSF II in exchange for cash in the amount of $75.7 million and an $6.6 million equity interest in PTSF II representing 23.1% of the total outstanding Class A Units of PTSF II. We recognized $0.2 million of realized gain upon the formation of PTSF II. As of September 30, 2025, our capital commitment of $15.0 million is 100% funded and we hold 23.1% of the total outstanding Class A Units of PTSF II and a 4.99% voting interest in the general partner which manages PTSF II. We are operated by a person who has claimed an exclusion from the definition of the term “commodity pool operator” under the Commodity Exchange Act and the Investment Adviser intends to continue to affirm the exclusion on an annual basis, and therefore, is not subject to registration or regulation as a commodity pool operator under the Commodity Exchange Act.

Organization

12 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. ORGANIZATION

PennantPark Investment Corporation was organized as a Maryland corporation in January 2007. We are a closed-end, externally managed, non-diversified investment company that has elected to be treated as a BDC under the 1940 Act. Our investment objective is to generate both current income and capital appreciation while seeking to preserve capital through debt and equity investments. We invest primarily in U.S. middle-market companies in the form of first lien secured debt, second lien secured debt, subordinated debt and, to a lesser extent, equity investments. On April 24, 2007, we closed our initial public offering. On April 14, 2022, listing and trading of the Company's common stock commenced on the New York Stock Exchange after the Company voluntarily withdrew the principal listing of its common stock from the Nasdaq Stock Market LLC effective at market close on April 13, 2022. Our common stock trades on the New York Stock Exchange under the symbol “PNNT.”

We execute our investment strategy directly and through our wholly owned subsidiaries, our unconsolidated joint venture and unconsolidated limited partnership. The term “subsidiary” means entities that primarily engage in investment activities in securities or other assets and are wholly owned by us. The Company does not intend to create or acquire primary control of any entity which primarily engages in investment activities of securities or other assets other than entities wholly owned by the Company. We comply with the provisions of Section 18 of the 1940 Act governing capital structure and leverage on an aggregate basis with our subsidiaries. Our subsidiaries comply with the provisions of Section 17 of the 1940 Act related to affiliated transactions and custody. To the extent that the Company forms a subsidiary advised by an investment adviser other than the Investment Adviser, the investment adviser to such subsidiaries will comply with the provisions of the1940 Act relating to investment advisory contracts, including but not limited to, Section 15, as if it were an investment adviser to the Company under Section 2(a)(20) of the 1940 Act.

We have entered into an investment management agreement, (the "Investment Management Agreement"), with PennantPark Investment Advisors, LLC (the "Investment Adviser"), an external adviser that manages our day-to-day operations. We have also entered into an administration agreement, (the "Administration Agreement"), with PennantPark Investment Administrator LLC (the "Administrator"), which provides the administrative services necessary for us to operate. PennantPark Investment, through the Administrator, also provided similar services to SBIC II under a separate administration agreement.

On July 31, 2020, we and certain entities and managed accounts of the private credit investment manager of Pantheon Ventures (UK) LLP (“Pantheon”) entered into a limited liability company agreement to co-manage PSLF, a newly-formed unconsolidated joint venture. In connection with this transaction, we contributed in-kind our formerly wholly-owned subsidiary, Funding I. As a result of this transaction, Funding I became a wholly-owned subsidiary of PSLF and has been deconsolidated from our financial statements. PSLF invests primarily in middle-market and other corporate debt securities consistent with our strategy. PSLF was formed as a Delaware limited liability company. See Note 4.

In April 2021, we issued $150.0 million in aggregate principal amount of our 2026 Notes at a public offering price per note of 99.4%. Interest on the 2026 Notes is

paid semi-annually on May 1 and November 1 of each year, at a rate of 4.50% per year, commencing November 1, 2021. The effective interest rate is 4.62%. The 2026 Notes mature on May 1, 2026 and may be redeemed in whole or in part at our option subject to a make-whole premium if redeemed more than three months prior to maturity. The 2026 Notes are general, unsecured obligations and rank equal in right of payment with all of our existing and future senior unsecured indebtedness. The 2026 Notes are effectively subordinated to all of our existing and future secured indebtedness to the extent of the value of the assets securing such indebtedness and structurally subordinated to all existing and future indebtedness and other obligations of any of our subsidiaries, financing vehicles, or similar facilities. We do not intend to list the 2026 Notes on any securities exchange or automated dealer quotation system.

In October 2021, we issued $165.0 million in aggregate principal amount of our 2026 Notes-2 at a public offering price per note of 99.4%. Interest on the 2026 Notes is paid semi-annually on May 1 and November 1 of each year, at a rate of 4.00% per year, commencing May 1, 2022. The effective interest rate is 4.12%. The 2026 Notes-2 mature on November 1, 2026 and may be redeemed in whole or in part at our option subject to a make-whole premium if redeemed more than three months prior to maturity. The 2026 Notes-2 are general, unsecured obligations and rank equal in right of payment with all of our existing and future senior unsecured indebtedness. The 2026 Notes-2 are effectively subordinated to all of our existing and future secured indebtedness to the extent of the value of the assets securing such indebtedness and structurally subordinated to all existing and future indebtedness and other obligations of any of our subsidiaries, financing vehicles, or similar facilities. We do not intend to list the 2026 Notes-2 on any securities exchange or automated dealer quotation system.

On November 22, 2021, we formed PNNT Investment Holdings II, LLC, a Delaware limited liability company (“Holdings II”), as a wholly owned subsidiary. On December 31, 2022, we contributed 100% of our interests in PNNT Investment Holdings, LLC (“Holdings”) to Holdings II . Effective as of January 1, 2024, Holdings II made an election to be treated as a corporation for U.S. federal income tax purposes. On January 3, 2024, we purchased an equity interest in Holdings from Holdings II and Holdings became a partnership for U.S. federal income tax purposes. The Company and Holdings II entered into a limited liability company agreement with respect to Holdings that provides for certain payments and the sharing of income, gain, loss and deductions attributable to Holdings’ investments.

In January 2022, we funded PennantPark-TSO Senior Loan Fund II LP, ("PTSF II"), an unconsolidated limited partnership, organized as a Delaware limited liability partnership. We sold $82.3 million in investments to a wholly-owned subsidiary of PTSF II in exchange for cash in the amount of $75.7 million and an $6.6 million equity interest in PTSF II representing 23.1% of the total outstanding Class A Units of PTSF II. We recognized $0.2 million of realized gain upon the formation of PTSF II. As of September 30, 2025, our capital commitment of $15.0 million is 100% funded and we hold 23.1% of the total outstanding Class A Units of PTSF II and a 4.99% voting interest in the general partner which manages PTSF II.

We are operated by a person who has claimed an exclusion from the definition of the term “commodity pool operator” under the Commodity Exchange Act and the Investment Adviser intends to continue to affirm the exclusion on an annual basis, and therefore, is not subject to registration or regulation as a commodity pool operator under the Commodity Exchange Act.