There were 171 state legislative vacancies across 43 states in 2021, according to a Ballotpedia analysis. As of Jan. 6, 2022, 129 of those vacancies have been filled.
One hundred and twenty-four (124) vacancies occurred in state Houses and 47 occurred in state Senates. Ninety (90) of the vacant seats were originally held by Democrats and 81 were originally held by Republicans.
Seventy-nine (79) vacancies occurred in states that fill vacancies through appointments, 81 occurred in states that fill vacancies through special elections, and 11 occurred in states that fill vacancies through a hybrid system that uses both appointments and special elections.
Arizona had the highest number of vacancies (13), followed by New Hampshire (11) and Oregon (10).
The most common reasons for a state legislative vacancy include an officeholder resigning, dying, leaving for a new job, being elected or appointed to a different office, or receiving a legal conviction. In 2021, Ballotpedia identified 90 state legislative vacancies that were caused by resignations, 52 caused by officeholders being appointed or elected to other offices, 25 caused by deaths, and four caused by removal.
Ballotpedia identified 146 state legislative vacancies in 42 states in 2020 and 177 vacancies in 45 states in 2019.