N.H. Rev. Stat. § 100-C:6
Regardless of a member's length of service, any member who becomes permanently and totally disabled may apply to the board of trustees to retire on a disability retirement allowance not less than 30 nor more than 90 days subsequent to the filing of such application. Such application shall be granted provided that a physician or physicians designated by the board of trustees, after a medical examination of such member, certifies that the member is mentally or physically incapacitated for further performance of duty, that such incapacity is likely to be permanent, and that such person should be retired. A member's disability retirement allowance shall be equal to 70 percent of the member's final year's salary.
RSA 100-C:6
2003, 311:1, eff. July 1, 2003.