Md. Code, Local Government § 4–409

(a) At any time within 45 days after enactment of an annexation resolution,

at least 20% of the qualified voters of the municipality may petition the chief

executive and administrative officer of the municipality in writing for a referendum

on the resolution.

(b) After a petition is presented to the chief executive and administrative

officer, the officer shall verify:

(1) the signatures on the petition; and

(2) that the petition meets the requirements of subsection (a) of this

section.

(c) After verifying compliance with the requirements of this section, the

chief executive and administrative officer, by proclamation, shall suspend the

effectiveness of the annexation resolution pending the results of the referendum.