I requested and received an absentee ballot. I did not fill it out or use it. The primaries for my state (Maryland) are today. Can I vote in person since I did not use my absentee ballot? If not, what are my options?
Generally yes. you are entitled to vote. They may give you a provisional ballot, that will really only be counted if the margins are close enough. If that provisional ballot is needed they can make the determination if your absentee ballot was cast or not.
It is also possible they will take your vote as is and verify the absentee ballots versus the roles of the election hall should it be needed. But a 2004 law guarantees you a chance to cast your ballot with the onus on the state board of elections to determine if you vote is legitimate.