R.I. Gen. Laws § 44-18.1-30 — Effective date for rate changes

Each member state shall provide that the effective date of rate changes for services
covering a period starting before and ending after the statutory effective date shall
be as follows:
(A) For a rate increase, the new rate shall apply to the first billing period starting
on or after the effective date.
(B) For a rate decrease, the new rate shall apply to bills rendered on or after the effective
date.