R.I. Gen. Laws § 30-3-37: Retirement of enlisted persons.

Any enlisted person who shall have served in the national guard for fifteen (15) years may, upon his or her own application to the commander-in-chief, be placed upon the retired list of enlisted persons and withdrawn from active service; provided, however, that if an enlisted person served in active federal service during World War I, World War II or the Korean Emergency and enlisted in the national guard within six (6) months from the time of discharge from active federal service, that person shall be entitled to have the intervening period counted as state service for the purposes of this section.