X0609 4 2026-09-03 0 0002021880 HMH Holding Inc HMH 0001228420 RETTIG DWIGHT W false 3300 NORTH SAM HOUSTON PARKWAY EAST HOUSTON TX 77032 0 1 0 0 Chf Admn Officer, GC, Corp Sec 0 Class A Common Stock 2026-09-03 4 A 0 10927 19.26 A 109295 D Class A Common Stock 2026-09-03 4 F 0 4300 19.26 D 104995 D On April 2, 2026, the reporting person was granted 10,927 performance-based restricted stock units, each of which represented a contingent right to receive one share of Class A common stock, par value $0.01 per share, of HMH Holding Inc. (the "Issuer"). The restricted stock units could be earned up to 200% of target depending on the Issuer's EBITDA growth as compared to the EBITDA growth of a set of peer companies over the three-year period from September 1, 2023 through August 31, 2026 and subject to the reporting person's continued service throughout such three-year period. On September 3, 2026, the Compensation Committee of the Board of Directors of the Issuer certified achievement of the performance condition at 50%, resulting in the restricted stock units originally granted becoming earned at 100% of the target amount granted. Represents shares of Class A common stock, par value $0.01 per share of the Issuer withheld to satisfy tax withholding obligations upon the vesting performance-based restricted stock units. This net settlement was approved by the board of directors of the Issuer pursuant to Rule 16b-3 under the Securities Exchange Act of 1934, as amended. /s/ Dwight W. Rettig 2026-09-04