Texas Local Government Code - LOC GOV'T § 87.042. County Commissioner Vacancy

(a) Except as provided by Subsection (b), if a vacancy occurs in the office of county commissioner, the county judge shall appoint a suitable resident of the precinct in which the vacancy exists to fill the vacancy until the next general election.

(b) This subsection applies only to a county with a population of more than 300,000. Not later than the 60th day after the date a vacancy occurs in the office of county commissioner, the county judge shall appoint a suitable resident of the precinct in which the vacancy exists to fill the vacancy until the next general election. If the county judge does not make an appointment to fill the vacancy before the 61st day after the date the vacancy occurred, the commissioners court by majority vote shall appoint a suitable resident of the precinct in which the vacancy exists to fill the vacancy until the next general election.