X0306 4 2022-05-12 0001701732 Altair Engineering Inc. ALTR 0001865998 Anderson James Francis C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER ROAD TROY MI 48083 1 Class A Common Stock 2022-05-12 4 A 0 3934 0 A 9908 D On May 12, 2022, the Reporting Person was granted 3,934 Class A Common Stock restricted stock units, which will vest on May 12, 2023. Each restricted stock unit represents a contingent right to receive one share of Class A Common Stock. Includes 9,908 Class A Common Stock restricted stock units that are unvested. /s/ Raoul Maitra, attorney-in-fact for James Francis Anderson 2022-05-13