An active member of the General Assembly Retirement System or the Judges Retirement System having no service credits or creditable service in the System, may establish service credit and creditable service for periods during which he was an employee and did not participate in the System. Service credits and creditable service may be established by payment to the System of an amount equal to the contributions he would have made if he had participated, plus regular interest to the date of payment, together with a like amount representing the employer contributions. The total period of such creditable service that may be validated shall not exceed 8 years.
40 ILCS 5/14-105.2