Maryland Code, Corporations and Associations § 5-112

(a) A corporation may elect to be a professional corporation under this subtitle by including in the articles of incorporation a statement that:

(b) A corporation incorporated in the State may elect professional corporation status by amending its articles of incorporation to comply with subsection (a) of this section and §§ 5-106 through 5-108 of this subtitle.

(c) A corporation that, prior to the effective date of this subtitle, was a duly organized professional corporation in the State shall be deemed a duly organized professional corporation under this subtitle.