Maryland Education Section 6-507

      (a)      (1)      The designation of an exclusive representative shall be for at least 2 years.

            (2)      After this initial period, the organization shall be the exclusive representative until another election is held.

      (b)      (1)      An election after the initial period of representation may be held:

                  (i)      Only after the end of the 2-year period; and

                  (ii)      On petition signed by more than 20 percent of the public school employees in the unit of the county.

            (2)      This election shall be held in the same manner as provided in § 6-506 of this subtitle.

            (3)      All signatures on a petition requesting an election shall be obtained within 90 days before the election date.