Does a mail-in ballot stay valid if the voter died between mailing it validly and the election date?
For some states, yes. For others, no.
What If an Absentee Voter Dies Before Election Day?, October 20, 2020
What happens when an eligible voter casts an absentee ballot and then passes away before Election Day? This question comes up more and more, as absentee/mail voting, and even early in-person voting, gain in popularity.
Do these pre-Election Day votes count? Like everything else related to elections, the answer varies from state to state. By our count, statutes in at least 13 states (Arkansas, Connecticut, Idaho, Florida, Louisiana, Maryland, Massachusetts, Minnesota, Montana, New Mexico, North Dakota, Tennessee and Virginia) direct election officials to count these ballots.
Again by our count, 13 states go the other way and are clear that these ballots are not to be counted: Delaware, Hawaii, Illinois, Indiana, Iowa, Kentucky (by an AG’s opinion, 77-667), Mississippi, Missouri, New Hampshire, New Jersey, Pennsylvania, South Dakota and Wisconsin.
Catching a ballot, then, is only possible for ballots that are still in their return envelopes. How quickly do election officials get notice of deaths? Fortunately, most statutes make it clear that these ballots are to be rejected only if the election administrators know about the death—and also that if a vote is counted that shouldn’t have been, it does not invalidate the election.