X0306 4 2022-02-15 0001701732 Altair Engineering Inc. ALTR 0001720686 Chouinard Brett R C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER RD. TROY MI 48083 1 1 See Remarks Class A Common Stock 2022-02-15 4 A 0 2850 0 A 16078 D Stock Option (Right to Buy) 61.79 2022-02-15 4 A 0 8500 0 A 2032-02-15 Class A Common Stock 8500 8500 D On February 15, 2022, the Reporting Person was granted 2,850 Class A Common Stock restricted stock units, which vest in 4 equal annual installments commencing February 15, 2023. Includes 12,305 Class A Common Stock restricted stock units that are unvested. On February 15, 2022, the Reporting Person was granted 8,500 Class A Common Stock options, the options vest in 4 equal annual installments commencing February 15, 2023. Chief Product and Strategy Officer /s/ Raoul Maitra, attorney-in-fact for Brett R. Chouinard 2022-03-16