N.J. Stat. § 30:4-73
The county from which any patient is committed shall be chargeable with the cost of the care and maintenance of any such patient committed to a State institution until the court shall find as a fact and the final judgment of commitment shall set forth whether the patient or his legally responsible relatives are able to pay the cost of his hospitalization and has a legal settlement in the county or has such legal settlement but is found able to pay.
If the patient has no such legal settlement in the county then said county shall receive a credit adjustment to reimburse it for any such charges made against it for any such patient. If the judgment is made by the court of another county, certified copies of the same shall be filed with the clerk of the county charged and the county adjuster of that county. If it shall appear that the patient has a legal settlement in some other county then the cost of clothing and maintenance of any indigent patient which may have accrued prior to the determination of legal settlement in any county shall be paid by the county in which the settlement is determined to be. When a patient is admitted to an institution and dies or is removed therefrom for any cause before final hearing, the court having jurisdiction is authorized to make a judicial finding as to his admission, legal settlement and ability to pay for the purpose of providing for payment of maintenance and clothing during the patient's confinement.
N.J.S. § 30:4-73