Maryland voters will decide in November whether to allow residents to register and vote at their polling places on Election Day.
The Senate voted 33-14 Monday night to put the constitutional amendment on the ballot. The House already has passed it.
A constitutional amendment doesn't need the governor's signature, so it will be on the ballot in November.
More than a dozen states allow Election Day voter registration.
Maryland already allows registering and voting on the same day during early voting.