X0609 4 2026-09-24 0 0001443669 Proto Labs Inc PRLB 0001894753 Schumacher Daniel false 5540 PIONEER CREEK DRIVE MAPLE PLAIN MN 55359 0 1 0 0 Chief Financial Officer 1 Common Stock 2026-09-24 4 S 0 5000 95.3209 D 35019 D This transaction was executed pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 5, 2026. Reflects the weighted average price of 5,000 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on September 24, 2026, with sale prices ranging from $95.00 to $95.65 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. /s/ W. Morgan Burns, Attorney-in-Fact 2026-09-25