Golub Capital Private Income Fund S

Item 1.01. Entry into a Material Definitive Agreement. BANA Credit Facility Amendment On September 30, 2026, GPIF S Funding (“Funding”), a wholly-owned subsidiary of Golub Capital Private Income Fund S (the “Company”), entered into a first amendment (the “Amendment”) to the revolving credit and security agreement (as amended and restated on December 31, 2025, the “BANA Credit Facility”) by and among Funding, as borrower, the Company, as servicer, Bank of America, N.A., as administrative agent and sole lender, and Computershare Trust Company, N.A., as collateral custodian. The Amendment, among other things, temporarily amends the Aggregate Commitments (as such term is defined in the Amendment) under the BANA Credit Facility from September 30, 2026 through August 16, 2027 (or an earlier date agreed among the administrative agent, the required lenders and Funding). The foregoing description of the Amendment is not complete and is qualified in its entirety by reference to the full text of the Amendment, which is attached hereto as Exhibit 10.1.