N.J. Stat. Ann. § 48:16A-8

If it shall appear to the Commissioner of Banking and Insurance, after a hearing, that the company no longer has a paid up cash capital of at least $300,000.00 and is no longer able to pay damages which may result from an accident occurring by reason of the ownership, maintenance or use of the vehicles owned by it, upon any public street, he shall revoke his order granting exemption. Thereupon the company shall immediately file an insurance policy or bond as required by sections 2 and 3 of this act.