X0609 4 2026-05-18 0002021880 HMH Holding Inc HMH 0001228420 RETTIG DWIGHT W false 3300 NORTH SAM HOUSTON PARKWAY EAST HOUSTON TX 77032 false true false false Chf Admn Officer, GC, Corp Sec false Class A Common Stock 2026-05-18 4 F false 39779 19.28 D 77694 D Class A Common Stock 2026-06-19 4 A false 24116 0.00 A 101810 D Represents shares of Class A common stock, par value $0.01 per share ("Class A Common Stock"), of HMH Holding Inc. (the "Issuer") withheld to satisfy tax withholding obligations upon the vesting of 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. Represents restricted stock units granted to the reporting person under the HMH Holding Inc. 2026 Long-Term Incentive Plan on June 19, 2026. Each restricted stock unit represents a contingent right to receive one share of Class A Common Stock. The restricted stock units vest in three equal installments on September 19, 2027, June 19, 2028 and June 19, 2029. /s/ Dwight W. Rettig 2026-06-23