N.H. Rev. Stat. § 102:9
At the beginning of each fiscal year the retirement board shall fix the assessment upon the annual salaries of all permanent firemen who accept the provisions of this chapter. The rate of assessment shall be 5- 1/2 percent of each permanent fireman's annual salary who was appointed a permanent fireman previous to July 1, 1948, unless the retirement board shall establish a different rate. The retirement board may vary the rate, based upon actuarial tables established by it. The retirement board may change, from time to time, the actuarial table of assessments, if it finds such change necessary, based upon periodic actuarial valuations of the retirement system. In the cases of permanent firemen who accept this chapter or become subject thereto at ages in excess of 35 years, the retirement board shall establish individual rates of assessment based upon the respective ages of such persons and sound actuarial principles. The board shall, in such manner as it may prescribe, give notice of the amount of assessment on each permanent fireman's salary to the treasurer or other disbursing officer of the city, town or precinct where such permanent fireman is employed. All assessments under this section and the following section shall be payable in equal monthly installments on the last business day of each calendar month. It shall be the duty of the treasurer or other disbursing officer of a city, town or precinct which employs permanent firemen who accept the provisions of this chapter to withhold from the monthly salary of each such permanent fireman, and to pay to the retirement board an amount equal to the monthly assessment against such permanent fireman's salary, as before provided. All permanent firemen who shall accept the provisions hereof, by such acceptance agree that the treasurer or other disbursing officer shall have the power to withhold from their monthly salaries the amounts as aforesaid.
RSA 102:9
1941, 192:9. RL 220:9. 1947, 54:2. RSA 102:9. 1957, 15:1, eff. July 1, 1957.