Main Street Capital to pay supplemental dividend in September

Board of Directors declared a supplemental cash dividend of $0.30 per share payable in September 2025. This supplemental cash dividend, which will be payable as set forth in the table below, will be paid out of Main Street's undistributed taxable income (taxable income in excess of dividends paid) as of June 30, 2025.

Supplemental Cash Dividend Payable in September 2025
Declared	Ex-Dividend Date	Record Date	Payment Date	Amount Per Share
8/4/2025	9/19/2025	9/19/2025	9/26/2025	$0.30