N.H. Rev. Stat. Ann. § 100-A:19-g

Upon accidental disability retirement as provided in RSA 100-A:6, I(c) or II(c) of any member in service who has creditable service in both group I and group II, if the member is a group I member at the time of retirement and has attained age 60, the accidental disability retirement allowance shall be equivalent to a split-benefit service retirement allowance as provided in RSA 100-A:19-c; otherwise, the accidental disability allowance shall be as provided in RSA 100-A:6, I(d) or II(d) depending on the member's group classification at the time of retirement.