Me. Rev. Stat. tit. 24-A, § 2385-E

A corporation, partnership, sole proprietorship or other business entity that provides staff, personnel or employees to be employed in the State to other businesses pursuant to a lease arrangement or agreement must, before becoming eligible to be issued a policy of workers' compensation insurance, register with the superintendent pursuant to Title 32, chapter 125. Employee leasing companies are subject to rules applicable to workers' compensation insurance as adopted by the superintendent and to penalties as defined in Title 32, section 14058.