X0306 4 2022-03-22 0001701732 Altair Engineering Inc. ALTR 0001720314 Scapa James Ralph C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER RD. TROY MI 48083 1 1 1 Chief Executive Officer Class A Common Stock 2022-03-22 4 A 0 23000 0 A 159269 D Class A Common Stock 1495 I By wife Stock Option (Right to Buy) 64.54 2022-03-22 4 A 0 80000 0 A 2032-03-22 Class A Common Stock 80000 80000 D On March 22, 2022, the Reporting Person was granted 23,000 Class A Common Stock restricted stock units, which vest in 4 equal annual installments commencing March 22, 2023. Includes 51,000 Class A Common Stock restricted stock units that are unvested. Includes 752 Class A Common Stock restricted stock units that are unvested. On March 22, 2022, the Reporting Person was granted 80,000 Class A Common Stock options, the options vest in 4 equal annual installments commencing March 22, 2023. /s/ Raoul Maitra, attorney-in-fact for James R. Scapa 2022-03-23