Minn. Stat. § 352.23: TERMINATION OF RIGHTS; REPAYMENT OF REFUND.

(a) When any employee accepts a refund as provided in section 352.22, all existing allowable service credits and all rights and benefits to which the employee was entitled before accepting the refund terminate.

(b) Terminated service credits and rights must not again be restored until the former employee acquires at least six months of allowable service credit after taking the last refund and repays all refunds previously taken from the retirement fund with interest as provided in paragraph (d). An employee will not be considered as entitled to any other benefit, including benefits for which the employee may be eligible because of the employee's original hire date into public employment, until full repayment of all refunds has been made.

(c) Repayment of refunds entitles the employee only to credit for service covered by (1) salary deductions; (2) payments previously made in lieu of salary deductions as permitted under law in effect when the payment in lieu of deductions was made; (3) payments made to obtain credit for service as permitted by laws in effect when payment was made; and (4) allowable service previously credited while receiving temporary workers' compensation as provided in section 352.01, subdivision 11, paragraph (a), clause (3).

(d) Payments under this section for repayment of refunds are to be paid with interest at the applicable annual rate or rates specified in section 356.59, subdivision 2, compounded annually, from the date the refund was taken until the date the refund is repaid. Repayment may be made in a lump sum during employment or up to six months after termination from service.