Maryland Code, Election Law § 3-302

(a)(1) Except as provided under §§ 3-305 and 3-306 of this subtitle, registration is closed during the period specified in this subsection.

(2) Voter registration closes beginning on the 21st day preceding an election at:

(3) Voter registration reopens on the 11th day after an election.

(1) there is sufficient evidence, as determined by the local board pursuant to regulations adopted by the State Board, that the application was mailed on or before registration was closed for that election; or

(2) the application was submitted by the voter to the Motor Vehicle Administration, a voter registration agency, another local board, or the State Board prior to the close of registration.