Md. Code, Local Government § 4–408

(a) Subject to § 4–413 of this subtitle, at any time within 45 days after

enactment of an annexation resolution, at least 20% of the registered voters who are

residents in the area to be annexed 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.