Maryland Code, Labor and Employment § 9-219

(a) Unless an election is made in accordance with this section, a partner of a partnership is not a covered employee.

(b) A partnership may elect to make a partner a covered employee if the partner devotes full time to the business of the partnership.

(c) An election under this section is not effective until the partnership submits to the Commission and to the insurer of the partnership a written notice that names the individual to be a covered employee.