R.I. Gen. Laws § 45-21.2-5.1: Retirement credits for layoffs.

(a) Members who are laid off for any reason, and not on leave without pay, may purchase layoff time up to one year service credit for retirement purposes, provided the member did not withdraw his or her retirement contributions while on the layoff, and returns to active service.

(b) Provided, further, that the member purchases the credit within one year of the member’s return to service from the layoff and (1) for purchases on or prior to June 30, 2012, the member pays into the retirement system in a lump sum the amount the member would have contributed to the system but for the layoff plus regular interest and (2) for purchases on or after July 1, 2012, the member pays into the retirement system in a lump sum the full actuarial cost of the time being purchased.

(c) The retirement board shall fix and determine rules and regulations to govern the provisions of this section.