94-411-803 Me. Code R. § 14
If a person who is a recipient of a service retirement benefit under The Plan returns to employment by a participating local district of The Plan in a position for which membership would be mandatory or optional for a new hire, the person continues to receive the service retirement benefit and does not re-enter The Plan as a member. During the period that a retiree is returned to employment, contributions must be remitted to the System by the participating local district in the amount of the greater of (i) 5% of the person's earnable compensation, or (ii) the equivalent of employer and employee unfunded actuarial liability contributions at the aggregate rate on the person's earnable compensation. For purposes of this section, earnable compensation does not include Workers' Compensation earnings paid to the person.
94-411 C.M.R. ch. 803, § 14