NGS SC 13DA

Exhibit 99.1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D dated November 28, 2022 (including amendments thereto) with respect to the Common Stock of Natural Gas Services Group, Inc. This Joint Filing Agreement shall be filed as an Exhibit to such Statement.

Dated: January 11, 2023

Hoak Public Equities, L.P.		Hoak Fund Management, L.P.
By:	Hoak Fund Management, L.P., its general partner	By:	Hoak & Co., its general partner
By:	Hoak & Co., its general partner	By:	/s/ J. Hale Hoak
			J. Hale Hoak
By:	/s/ J. Hale Hoak		President
	J. Hale Hoak
	President
Hoak & Co.		James M. Hoak
By:	/s/ J. Hale Hoak	By:	/s/ James M. Hoak
	J. Hale Hoak		James M. Hoak
	President
J. Hale Hoak
By:	/s/ J. Hale Hoak
	J. Hale Hoak