Subdivision (1) of section 4 of chapter 32 of the General Laws, as appearing in the 2014 Official Edition, is hereby amended by inserting after clause (r), the following clause:-

(r ½) Notwithstanding any general or special law to the contrary, a member in service, as defined in section 3, who served in the Commissioned Corps of the United States Public Health Service or the Commissioned Corps of the National Oceanic and Atmospheric Administration, who has completed 4 or more years of membership service, as defined in section 1, shall receive full credit for the period of such Commissioned Corps service for purposes of retirement; provided, however, that they retire on or after January 1, 1975. Eligibility for the creditable service shall be conditioned upon payment, in 1 sum or in installments upon such terms as the applicable retirement board may provide, into the annuity savings fund of the applicable retirement system, of an amount equal to the contributions such member in service would have otherwise paid into the retirement system plus buyback interest thereon, for the period of Commissioned Corps service based upon the annual salary the member received in the first year of membership service after his or her Commissioned Corps service.