Maryland Election Law Section 5-303

      (a)      Except as provided in subsections (b) and (c) of this section, a certificate of candidacy shall be filed as follows:

            (1)      for candidates for offices other than delegate to the Democratic National Convention, not later than 9 p.m. on the Monday that is 10 weeks or 70 days before the day on which the primary election will be held; and

            (2)      for candidates for delegate to the Democratic National Convention, between 9 a.m. on the first regular business day of the year in which the President of the United States is elected and 5 p.m. on the day that is 1 week later than that day.

      (b)      A certificate of candidacy for an office to be filled by a special election under this article shall be received and filed in the office of the appropriate board not later than 5 p.m. on the Monday that is 3 weeks or 21 days prior to the date for the special primary election specified by the Governor in the proclamation for the special primary election.

      (c)      The certificate of candidacy for the election of a write-in candidate shall be filed by the earlier of:

            (1)      7 days after a total expenditure of at least $51 is made to promote the candidacy by a campaign finance entity of the candidate; or

            (2)      5 p.m. on the Wednesday preceding the day of the election for which the certificate is filed.