Some states, including Missouri, require voters to provide a valid excuse in order to receive an absentee ballot in the mail as an alternative to in-person voting. Other states allow voters to request a ballot without any excuse, or automatically mail all voters a ballot. Due to the COVID-19 pandemic, many states expanded the availability of absentee voting for the 2020 primary and presidential elections. As a result, the use of mail-in ballots nearly doubled with respect to previous election years. Studies have shown that allowing all registered voters to request a mail-in ballot without any excuse requirement can result in a moderate increase in voter turnout. There have been no indications that mail-in ballots are associated with large increases in the share of votes obtained by one party or with increases in voter fraud.