X0306 4 2020-03-12 0 0001766368 Mayville Engineering Company, Inc. MEC 0001776003 Christen Timothy L 715 SOUTH STREET MAYVILLE WI 53050 1 0 0 0 Common Stock 2020-03-12 4 P 0 25000 4.5820 A 68000 D Director Restricted Stock Units 0 Common Stock 5883 5883 D The price in Column 4 is a weighted average price. The prices actually received ranged from $4.255 to $5.00. The reporting person has provided to the issuer, and will provide to any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares purchased at each price within the range for all transactions reported in this Form 4 utilizing an average weighted price. The restricted stock units will vest 100% on May 8, 2020. /s/ Russell E. Ryba, Attorney-in-Fact for Timothy L. Christen 2020-03-16