Michigan Compiled Laws, Chapter 450. Corporations § 450.1281

Sec. 281. (1) A corporation must incorporate as a professional corporation under this chapter if it is incorporated to provide 1 or more services in a learned profession, whether or not it is providing other professional services. A corporation may comply with this chapter and incorporate as a professional corporation if it is incorporated to provide 1 or more professional services, none of which are services in a learned profession, or may incorporate as a corporation that is not required to comply with this chapter.

(2) A corporation that is incorporated as a professional corporation and its shareholders are subject to this chapter and this act. If there is a conflict between an applicable provision of this chapter and another provision of this act, the provision of this chapter takes precedence.

(3) This chapter applies to a corporation incorporated under former 1962 PA 192,  1 or to a corporation that on the effective date of this chapter was governed by former 1962 PA 192 as if incorporated under that act, as if that corporation were incorporated under this act and pursuant to this chapter.

(4) This chapter does not apply to a corporation organized in this state before the enactment of former 1962 PA 192 to provide professional services to the public, and that did not previously amend its articles of incorporation to bring itself within the provisions of former 1962 PA 192, unless that corporation amends its articles of incorporation in such a manner that it is consistent with all the provisions of this chapter and affirmatively states in its amended articles of incorporation that the shareholders have elected to bring the corporation within the provisions of this chapter and this act.