R.I. Gen. Laws § 44-30-71.1: Voluntary withholding of tax from military retirement payments.

(a) The tax administrator may enter into agreements with the federal government to allow for the withholding from military retirement payments subject to Rhode Island personal income tax of a resident individual, an amount substantially equivalent to the tax reasonably estimated to be due resulting from the inclusion in the resident’s Rhode Island income of his or her retirement payments received during any calendar year.

(b) The method of determining the amount to be withheld shall be prescribed by regulations of the tax administrator, with due regard to the withholding exemptions of the resident.

(c) The provisions of this section shall apply only to a resident who so elects to have the withholding effected.