94- 411 C.M.R. ch. 410, § 8
Failure by any retiree who has not reached Normal Retirement Age to comply with Section 5, Section 7(2) or Section 7(3) of this rule will result in immediate suspension of the retiree's retirement benefit, if the retiree's noncompliance has prevented a timely suspension of benefits pursuant to Section 6 of this rule. The retiree must repay to MainePERS the amount of benefits paid, plus interest on that amount at the rate set by the Board for the purchase of service credit, during the period in which the retiree's benefit should have been suspended. MainePERS will collect the repayment owed from the retiree's retirement benefits whenever the benefits are no longer required to be suspended under Section 6. Monthly benefits paid after reinstatement will be decreased by an actuarial adjustment accounting for the overpayment of benefits. Instead of this adjustment, the retiree may elect to repay the amount due by making a lump sum payment of the repayment owed within 30 days of being notified by MainePERS that repayment is owed, which amount will not include interest.
94- 411 C.M.R. ch. 410, § 8