Subsequent Events	12 Months Ended
Dec. 31, 2025
Subsequent Events [Abstract]
Subsequent Events	12. SUBSEQUENT EVENTS Subsequent events after the date of the Consolidated Statements of Financial Condition have been evaluated through the date the consolidated financial statements were issued. Other than the items discussed below, the Company has concluded that there is no impact requiring adjustment or disclosure in the consolidated financial statements. Capital Drawdown On January 2, 2026, the Company delivered a capital drawdown notice to its investors relating to the issuance and sale of approximately 2.7 million common units for an aggregate offering price of approximately $52,500. Fifth Amendment to the Credit Facility On January 16, 2026, SPV entered into a fifth amendment (the “Fifth Amendment”) to the Credit Facility. The Fifth Amendment, among other things, increased the Facility Amount to $750 million, and amended certain components of the Borrowing Base, resulting in an increase to the Borrowing Base. Capitalized terms used but not otherwise defined herein have the meanings ascribed thereto in the Fifth Amendment. The description above is only a summary of the material provisions of the Fifth Amendment and is qualified in its entirety by reference to a copy of the Fifth Amendment, which was filed as Exhibit 10.1 to the Company’s current report on Form 8-K, dated January 22, 2026, the terms of which are incorporated herein by reference. Distribution The Company will pay a distribution equal to an amount up to the Company’s taxable earnings per Unit, including net investment income (if positive) for the period beginning January 1, 2026 through March 31, 2026, which will be payable on or about April 29, 2026 to Unitholders of record as of April 2, 2026. Phillip Street Middle Market Lending Fund LLC – Tax Information (unaudited) During the year ended December 31, 2025, the Company designated 98.10% of its distributions from net investment income as interest-related dividends pursuant to Section 871(k) of the Internal Revenue Code. During the year ended December 31, 2025, the Company designated 94.98% of the dividends paid from net investment company taxable income as section 163(j) Interest Dividends. Pursuant to Section 852 of the Internal Revenue Code, the Company designated $241,056 or if different, the maximum amount allowable, as capital gain dividends paid during the year ended December 31, 2025. During the year ended December 31, 2025, the Company designated $576,149 as short-term capital gain dividends pursuant to Section 871(k) of the Internal Revenue Code.

Subsequent Events

12 Months Ended

Dec. 31, 2025

12. SUBSEQUENT EVENTS

Subsequent events after the date of the Consolidated Statements of Financial Condition have been evaluated through the date the consolidated financial statements were issued. Other than the items discussed below, the Company has concluded that there is no impact requiring adjustment or disclosure in the consolidated financial statements.

Capital Drawdown

On January 2, 2026, the Company delivered a capital drawdown notice to its investors relating to the issuance and sale of approximately 2.7 million common units for an aggregate offering price of approximately $52,500.

Fifth Amendment to the Credit Facility

On January 16, 2026, SPV entered into a fifth amendment (the “Fifth Amendment”) to the Credit Facility. The Fifth Amendment, among other things, increased the Facility Amount to $750 million, and amended certain components of the Borrowing Base, resulting in an increase to the Borrowing Base. Capitalized terms used but not otherwise defined herein have the meanings ascribed thereto in the Fifth Amendment.

The description above is only a summary of the material provisions of the Fifth Amendment and is qualified in its entirety by reference to a copy of the Fifth Amendment, which was filed as Exhibit 10.1 to the Company’s current report on Form 8-K, dated January 22, 2026, the terms of which are incorporated herein by reference.

Distribution

The Company will pay a distribution equal to an amount up to the Company’s taxable earnings per Unit, including net investment income (if positive) for the period beginning January 1, 2026 through March 31, 2026, which will be payable on or about April 29, 2026 to Unitholders of record as of April 2, 2026.

Phillip Street Middle Market Lending Fund LLC – Tax Information (unaudited)

During the year ended December 31, 2025, the Company designated 98.10% of its distributions from net investment income as interest-related dividends pursuant to Section 871(k) of the Internal Revenue Code.

During the year ended December 31, 2025, the Company designated 94.98% of the dividends paid from net investment company taxable income as section 163(j) Interest Dividends.

Pursuant to Section 852 of the Internal Revenue Code, the Company designated $241,056 or if different, the maximum amount allowable, as capital gain dividends paid during the year ended December 31, 2025.

During the year ended December 31, 2025, the Company designated $576,149 as short-term capital gain dividends pursuant to Section 871(k) of the Internal Revenue Code.