Maryland Business Occupations and Professions Section 12-308
§ 12-308.
  (a)   Unless a license is renewed for a 2-year term as provided in this section, the license expires on the first May 1 that comes:
    (1)   after the effective date of the license; and
    (2)   in an odd-numbered year.
  (b)   At least 1 month before a license expires, the Board shall mail to the licensee, at the last known address of the licensee:
    (1)   a renewal application form; and
    (2)   a notice that states:
      (i)   the date on which the current license expires;
      (ii)   the date by which the Board must receive the renewal application for the renewal to be issued and mailed before the license expires; and
      (iii)   the amount of the renewal fee.
  (c)   Before a license expires, the licensee may renew it for an additional 2-year term, if the licensee:
    (1)   otherwise is entitled to be licensed;
    (2)   pays to the Board a renewal fee of:
      (i)   $70 for a master plumber license or a limited master plumber license;
      (ii)   $35 for a journey plumber license or a limited journey plumber license;
      (iii)   $15 for an apprentice plumber license or apprentice natural gas fitters license;
      (iv)   $35 for a propane gas fitter certificate;
      (v)   $35 for a master natural gas fitters license; or
      (vi)   $25 for a journeyman natural gas fitters license; and
    (3)   submits to the Board:
      (i)   if contracting in the name of the licensee or another person to provide plumbing services, proof of the liability insurance required under § 12-501 of this title; and
      (ii)   a renewal application on the form that the Board provides.
  (d)   The Board shall renew the license of and issue a renewal certificate to each licensee who meets the requirements of this section.
  (e)   The Secretary may determine that licenses and certificates issued under this subtitle shall expire on a staggered basis.