X0609 4 2026-10-19 0001437226 Mastech Digital, Inc. MHH 0001190614 SHAW STEVEN A false 346 CLAYPOOL DRIVE WARWICK RI 02886 false false true false false Common Stock 2026-10-19 4 P false 2500 6.44 A 57500 I By Rachel Lynn Shaw Trust Common Stock 2026-10-20 4 P false 2200 6.33 A 59700 I By Rachel Lynn Shaw Trust Common Stock 1310100 D This purchase was executed through multiple trades at prices ranging from $6.43 to $6.44. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price for all transactions reported on this Form 4. The reporting person is the trustee and a contingent residual beneficiary of the Rachel Lynn Shaw Trust. This purchase was executed through multiple trades at prices ranging from $6.31 to $6.38. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares purchased at each separate price for all transactions reported on this Form 4. /s/ Steven A. Shaw 2026-10-21