what US states do not require ID to vote in general elections
States where voters generally do not have to show ID at the polls for general elections are California, Illinois, Kentucky, Maryland, Massachusetts, Minnesota, New Mexico, New York, and Pennsylvania.
What that means
In those states, you can usually vote in person without presenting ID at the polling place, though some of them may still ask for ID if it is your first time voting or if there is a registration issue.
Important caveat
Voting rules can change, and some states use different rules for first-time voters, absentee/mail voting, or provisional ballots. The clearest current reporting I found says 38 states require some form of ID at the polls, which leaves these 9 states as the main no-ID-at-polls states for general in-person voting.
Quick note
This is about ID at the polling place, not whether you need ID to register, request a mail ballot, or prove citizenship under proposed federal changes.