Craig D. Nichols - 06 Nov 2025 Form 4 Insider Report for Mayville Engineering Company, Inc. (MEC)

Role: SVP, Operations & Supply Chain
Signature: /s/ Russell E. Ryba, Attorney-in-Fact for Craig D. Nichols
Issuer symbol: MEC
Transactions as of: 06 Nov 2025
Net transactions value: +$18,087
Form type: 4
Filing time: 07 Nov 2025, 16:36:40 UTC
Previous filing: 18 Mar 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Nichols Craig D	SVP, Operations & Supply Chain	135 SOUTH 84TH STREET, SUITE 300, MILWAUKEE	/s/ Russell E. Ryba, Attorney-in-Fact for Craig D. Nichols	07 Nov 2025	0002060070

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MEC	Common Stock	Award	$18,087	+1,134		$15.95	1,134	06 Nov 2025	by 401(k) Plan

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	MEC	Restricted Stock Units						17,422	06 Nov 2025	Common Stock	17,422	$0.000000	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The restricted stock units will vest 1/3 on each of March 15, 2026, 2027 and 2028.