X0306 4 2020-03-05 0 0001580156 Houghton Mifflin Harcourt Co HMHC 0001720813 Fields Matthew M. C/O HOUGHTON MIFFLIN HARCOURT CO., 125 HIGH STREET BOSTON MA 02110 0 1 0 0 See remarks. Common Stock 2020-03-05 4 M 0 6881 0.00 A 22205 D Common Stock 2020-03-05 4 F 0 2935 4.98 D 19270 D Restricted Stock Units 2020-03-05 4 M 0 6881 0.00 D Common Stock 6881 13764 D 6,881 restricted stock units held by Mr. Fields vested on March 5, 2020 and were settled in exchange for a like amount of shares of the Company's common stock, subject to the Company's withholding of 2,935 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 in two equal installments on March 5, 2021 and March 5, 2022, subject to continued employment with the Company. Executive Vice President, General Manager - Supplemental & Intervention Solutions. William F. Bayers is the Executive Vice President, Secretary and General Counsel of the Company. /s/ William F. Bayers, Attorney-in-Fact 2020-03-09