The term of office of a senator is 4 years or until a successor is elected and qualified, and the term of office of a representative is 2 years or until a successor is elected and qualified. The term of service begins on the first Monday of January following the election. If a senator is elected to fill a vacancy, the term of service begins on the day after the election.
Mont. Code Ann. § 5-2-102
Term of office
En
Official source: Montana Code Annotated (Montana Legislature). Reproduced from public-domain Montana statutes; confirm against the official source for the current text. Not legal advice.