OPINION ON MOTION TO DISMISS

Opinion by:

Susana Hernandez sued Harlandale Independent School District for violating the Texas Whistleblower Act. When the trial court denied Harlandale’s motion to dismiss, the school district

A governmental unit may appeal an interlocutory order that “grants or denies a plea to the jurisdiction.” Tex. Civ. PRAC. & Rem.Code Ann. § 51.014(a)(8) (Vernon Supp. 1999); see also id. § 101(3)(B) (defining a school district as a governmental unit). A plea to the jurisdiction is the appropriate procedural vehicle to challenge the trial court’s subject matter jurisdiction. City of Austin v. L.S. Ranch, Ltd., 970 S.W.2d 750, 752 (Tex.App.—Austin 1998, no pet.). A trial court lacks subject matter jurisdiction if a plaintiff fails to comply “with an existing grievance procedure” before suing under the Whistleblower Act. Permian Basin Community Ctrs. for Mental Health & Mental Retardation v. Johns, 951 S.W.2d 497, 502 (Tex.App.—El Paso 1997, no writ); 1 see also Essenburg v. Dallas County, 988 S.W.2d 188, 189 (Tex. 1998).

Harlandale’s motion to dismiss alleges that Hernandez failed to timely invoke the applicable grievance procedure. See Tex. Gov’t Code Ann. § 554.006(a-b) (Vernon Supp. 1999) (entitled “Use of Grievance or Appeal Procedures”). It does not allege that she failed to file suit within the applicable statute of limitations. See id. § 554.005 (Vernon 1994) (entitled “Limitation Period”). Because Harlan-dale’s motion questioned subject-matter jurisdiction, the school district may appeal the trial court’s denial of the motion. We therefore deny Hernandez’s motion to dismiss the appeal for lack of jurisdiction.