(1) An action for legal malpractice against an attorney-at-law or a law firm shall not be commenced after whichever of the following is earlier:

    (a) The expiration of the applicable period of limitations under this chapter.

    (b) Six years after the date of the act or omission that is the basis for the claim.

    (2) A legal malpractice action that is not commenced within the time prescribed by subsection (1) is barred.

    (3) As used in this section:

    (a) "Attorney-at-law" means an individual licensed to practice law in this state or elsewhere.

    (b) "Law firm" means a person that is primarily engaged in the practice of law, regardless of whether organized as a sole proprietorship, partnership, limited liability partnership, professional limited liability company, professional corporation, or other business entity. Law firm includes a legal services organization.