N.H. Rev. Stat. § 99:6-a
Any person who has been or is caused to leave state service involuntarily by reason of reduction in force and who returned or shall return to state service may for purposes of future compensation only, count the time of said prior state service as continuous with his present service without inclusion of the intervening period of non-state employment, to obtain benefits provided under RSA 94:4 and 99:5. This section shall not authorize retroactive payment to persons now or hereafter in state service affected hereby but shall provide credit of such past service for compensation subsequent to the effective date of this act. This section shall not apply to persons who shall have separated or separate from state service under other circumstances.
RSA 99:6-a
1955, 202:1, eff. July 1, 1955.