X0306 4 2022-03-09 0 0001580156 Houghton Mifflin Harcourt Co HMHC 0001716892 Dunkin Amy C/O HOUGHTON MIFFLIN HARCOURT 125 HIGH STREET BOSTON MA 02110 0 1 0 0 EVP, General Manager, Services Common Stock 2022-03-09 4 M 0 9501 0.00 A 56928 D Common Stock 2022-03-09 4 F 0 4185 21.04 D 52743 D Restricted Stock Units 2022-03-09 4 M 0 9501 0.00 D Common Stock 9501 9502 D 9,501 restricted stock units held by Ms. Duncan vested on March 9, 2022 and were settled in exchange for a like amount of shares of Houghton Mifflin Harcourt Company's (the "Company") common stock, subject to the Company withholding of 4,185 shares of common stock to satisfy withholding obligations in connection with federal, state, local or other taxes required to be withheld or paid in connection with the settlement of the restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Company's common stock. The remaining restricted stock units shall vest on March 9, 2023, subject to continued employment with the Company. William F. Bayers is the Executive Vice President, Secretary and General Counsel of the Company. s/ William F. Bayers, Attorney-in-Fact 2022-03-11