N.J. Stat. § 2A:53A-27
In any action for damages for personal injuries, wrongful death or property damage resulting from an alleged act of malpractice or negligence by a licensed person in his profession or occupation, the plaintiff shall, within 60 days following the date of filing of the answer to the complaint by the defendant, provide each defendant with an affidavit of an appropriate licensed person that there exists a reasonable probability that the care, skill or knowledge exercised or exhibited in the treatment, practice or work that is the subject of the complaint, fell outside acceptable professional or occupational standards or treatment practices. The court may grant no more than one additional period, not to exceed 60 days, to file the affidavit pursuant to this section, upon a finding of good cause.
In the case of an action for medical malpractice, the person executing the affidavit shall meet the requirements of a person who provides expert testimony or executes an affidavit as set forth in section 7 of P.L. 2004, c. 17(C.2A:53A-41). In all other cases, the person executing the affidavit shall be licensed in this or any other state; have particular expertise in the general area or specialty involved in the action, as evidenced by board certification or by devotion of the person's practice substantially to the general area or specialty involved in the action for a period of at least five years. The person shall have no financial interest in the outcome of the case under review, but this prohibition shall not exclude the person from being an expert witness in the case.
N.J.S. § 2A:53A-27