N.J. Stat. § 40A:14-12
Except as otherwise herein provided, no person shall be appointed as a member or officer of the paid fire department or force or as a paid member or officer of a part-paid fire department or force in any municipality, who is under 21 or over 35 years of age.
In any municipality wherein Title 11 (Civil Service) of the Revised Statutes is operative, any person who shall have met the age requirements herein, at the announced closing date of a civil service examination for the position, shall be considered within the age requirements while the civil service list promulgated as a result of that examination is in effect.
Nothing herein contained shall affect the employment or continuance in office of any person, as a permanent fireman, employed by said municipality prior to the adoption of the ordinance creating and establishing a paid or part-paid fire department or force.
The provisions of this section are subject to chapter 98 of the laws of 1944 (C. 38:23A-2), relating to maximum age limits for persons serving in the armed forces of the United States as therein provided.
N.J.S. § 40A:14-12