Exhibit 99 MAYVILLE ENGINEERING COMPANY ANNOUNCES FIRST QUARTER 2024 RESULTS MILWAUKEE, Wis., May 7, 2024 – Mayville Engineering Company (NYSE: MEC) (the “Company” or “MEC”), a leading value-added provider of design, prototyping and manufacturing solutions serving diverse end markets, today announced results for the three-months ended March 31, 2024. FIRST QUARTER 2024 RESULTS (All comparisons versus the prior-year period) ● Net sales of $161.3 million, or +13.1% y/y, including organic growth of 3.3% y/y ● ...