R.I. Gen. Laws § 36-9-2: Membership of persons employed after establishment of system.

All employees as defined in chapter 8 of this title who became employees on or after July 1, 1936, shall, under contract of their employment become members of the retirement system and shall receive no pension or retirement allowance from any other pension or retirement system supported wholly or in part by the state of Rhode Island, except as provided in chapter 10.3 of title 36 and § 36-9-3, nor shall they be required to make contributions under any other pension or retirement system of the state except as provided in chapter 10.3 of title 36, anything to the contrary notwithstanding; provided, however, that this section shall not apply to those employees who may be required or elect to participate in a retirement program existing by virtue of chapter 17.1 of title 16 or § 36-10-9.1.