N.J. Stat. Ann. § 18A:20-29

All moneys received by the insurance fund commissioners for premiums on school buildings and school property insured in the municipal insurance fund of the city, except so much as may be necessary to pay premiums upon insurance placed upon any of such school buildings and school property with insurance companies as provided in this subarticle, shall be invested by the commissioners with the moneys of the municipal insurance fund and in the manner provided by law for the investment of such moneys.