X0306 4 2017-11-15 0 0001396440 Main Street Capital CORP MAIN 0001069725 FOSTER VINCENT D 1300 POST OAK BLVD. 8TH FLOOR HOUSTON TX 77056 1 1 0 0 Chairman and CEO Common Stock 2017-11-15 5 G 0 E 30000 0.00 D 1507785.7521 D Common Stock 2017-11-15 5 G 0 E 30000 0.00 A 30000 I By MS V Common Stock 2017-11-15 5 J 0 E 6.8983 40.70 A 1507792.6504 D Common Stock 2017-11-15 5 J 0 E 1736.058 40.70 A 1509528.7084 D Common Stock 2017-11-15 5 J 0 E 73.0277 40.70 A 15716.3463 I By Foster Irrevocable Trust Common Stock 30000 I By MS I Common Stock 30000 I By MS II Common Stock 30000 I By MS III Common Stock 50000 I By MS IV Shares gifted to MS Trust V. Family trust. The reporting person acquired these shares under a dividend reinvestment plan, pursuant to a dividend reinvestment transaction exempt from Section 16 under Rule 16a-11. Represents shares held in MS Trust IV, a charitable trust where Mr. Foster is a trustee and holds the remainder interest therein. /s/ Jason B. Beauvais as Attorney-in-Fact for Vincent D. Foster 2017-11-29