Md. Code, Courts and Judicial Proceedings § 9–122

(a) A member of the General Assembly may not be subpoenaed to testify in a civil or administrative action, proceeding, or deposition, other than one in which the member is a named private party, during any regular or special session, and for 10 days before and after each session.

(b) This section does not constitute a waiver of a member’s constitutional or common law privileges.