N.J. Stat. § 43:16A-56
In the event the board of trustees shall determine to purchase group insurance coverage for the death benefits, premiums for the same shall be paid from a special fund, hereby created, called the "Group Insurance Premium Fund." The board of trustees shall estimate annually the amount which will be required for premiums for such benefits for the ensuing fiscal year and shall certify such amounts to the participating employers as due and owing from them. The participating employers shall pay over to the board of trustees the amount for premiums so certified and the board of trustees shall deposit these amounts in the Group Insurance Premium Fund. During the period such group insurance policy or policies are in effect with respect to members of the Police and Firemen's Retirement System of New Jersey the board of trustees shall in no way commingle moneys in this fund with any pension fund established by P.L. 1944, c.255 (C.43:16A-1 et seq.).
N.J.S. § 43:16A-56