Maryland Corporations and Associations Section 5-118
§ 5-118.
  (a)   Only a qualified person may be appointed a proxy to vote stock of a professional corporation.
  (b)   A voting trust with respect to stock of a professional corporation is not valid unless all of the trustees of the trust are stockholders of the professional corporation.
  (c)   Stock in a professional corporation may not be transferred into a trust, unless:
    (1)   All settlors of the trust remain stockholders of the professional corporation for the duration of the trust; and
    (2)   All trustees of the trust are individuals licensed in the State to render the professional service named in the professional corporation's articles of incorporation.
  (d)   (1)   If a settlor of stock in a professional corporation in a trust ceases to be a stockholder in the corporation, the settlor shall be a disqualified stockholder and the corporation shall acquire the stock held by the trust.
    (2)   An acquisition of stock under paragraph (1) of this subsection shall be made under §§ 15-113 through 15-115 of this subtitle.