X0306 4 2021-02-27 0 0001580156 Houghton Mifflin Harcourt Co HMHC 0001669907 Abbott Joseph Patrick Jr. C/O HOUGHTON MIFFLIN HARCOURT 125 HIGH STREET BOSTON MA 02110 0 1 0 0 EVP, Chief Financial Officer Common Stock 2021-02-27 4 M 0 26667 0.00 A 118313 D Common Stock 2021-03-01 4 S 0 14397 6.24 D 103.916 D Common Stock 2021-02-27 4 A 0 32382 0.00 A 136298 D Common Stock 2021-03-01 4 S 0 16940 6.24 D 119358 D Restricted Stock Units 2021-02-27 4 M 0 26667 0.00 D Common Stock 26667 0 D 26,667 restricted stock units held by Mr. Abbott vested on February 27, 2021 and were settled in exchange for a like amount of shares of Houghton Mifflin Harcourt Company's (the "Company") common stock, subject to the sale of 14,397 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. 32,382 performance stock units held by Mr. Abbott vested on February 27, 2021 and were settled in exchange for a like amount of shares of Company common stock, subject to the sale of 16,940 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 performance stock units. Each restricted stock unit represents a contingent right to receive one share of the Company's common stock. William F. Bayers is the Executive Vice President, Secretary and General Counsel of the Company. s/ William F. Bayers, Attorney-in-Fact 2021-03-02