Md. Code, Financial Institutions § 1–304

(a) In this section, “subpoena” means a subpoena, summons, warrant, or court order that appears on its face to have been issued on lawful authority.

(b) A fiduciary institution may disclose or produce financial records or information derived from financial records in compliance with a subpoena served on the fiduciary institution, if:

(1) The subpoena contains a certification that a copy of the subpoena has been served on the person whose records are sought by the party seeking the disclosure or production of the records; or

(2) Contains a certification that service has been waived by the court for good cause.