Definitions.

Sec. 601. Whenever used in this act: (a) "Insurer" means an organization that transacts the business of worker's compensation insurance within this state. (b) "Self-insurer" means either of the following: (i) An individual employer authorized to carry its own risk. (ii) A group of employers who pool their liabilities under this act as a group fund in the manner provided in section 611. (c) "Carrier" means a self-insurer or an insurer.