N.H. Rev. Stat. Ann. § 102:27

Any provision of RSA 100:24 notwithstanding any permanent fireman whose membership has been transferred from the state employees' retirement system to the firemen's retirement system in accordance with the provisions of this subdivision shall thereafter be eligible for such benefits as are provided under this chapter, as hereinabove amended, as if he had accepted the provisions of said chapter at the time of becoming a member of the state employees' retirement system.