Michigan Compiled Laws, Chapter 500. Insurance Code of 1956 § 500.106

(a) “Health maintenance organization” means that term as defined in section 3501.  1

(b) “Insurer” means an individual, corporation, association, partnership, reciprocal exchange, inter-insurer, Lloyds organization, fraternal benefit society, or other legal entity, engaged or attempting to engage in the business of making insurance or surety contracts.Except as otherwise provided in section 3503  2 and unless the context requires otherwise, insurer includes a health maintenance organization.