Md. Code, Election Law § 9–307

(a) A qualified applicant may designate a duly authorized agent to pick up and deliver an absentee ballot under this subtitle.

(b) An agent of the voter under this section:

(1) must be at least 18 years old;

(2) may not be a candidate on that ballot;

(3) shall be designated in a writing signed by the voter under penalty of perjury; and

(4) shall execute an affidavit under penalty of perjury that the ballot was:

(i) delivered to the voter who submitted the application;

(ii) marked and placed in an envelope by the voter, or with assistance as allowed by regulation, in the agent’s presence; and

(iii) returned to the local board by the agent.