Some of those changes are more substantial than others.
California, Nevada, New Jersey and Vermont, along with Washington, D.C., are sending mail-in ballots to all voters, joining the handful of states that conduct all-mail elections. In Montana, individual counties are now authorized to send voters ballots. And many more states are mailing voters absentee ballot applications.
There's also been a big expansion in who can vote absentee. Many states, including New Hampshire and New York, have suspended the need for an excuse to obtain an absentee ballot, or said fear of contracting COVID-19 while voting is a valid excuse.
Other states have altered deadlines and/or loosened rules for submitting an absentee ballot. In Virginia, for instance, an absentee ballot won't need a witness signature.
The map above gives a broad overview of mail-in voting procedures for each state. We'll update the map with any further changes, but be sure to check with your state for the most detailed and up-to-date voting information.
Changes to the map since its publish:
-- Sept. 16: South Carolina's new law allows all voters to vote absentee.
-- Sept. 17: Minnesota agrees to send absentee ballot applications to all voters.
This map was originally published on Sept. 14.