N.J. Stat. § 2C:14-6
If a person is convicted of a second or subsequent offense under sections 2C:14-2 or 2C:14-3a., the sentence imposed under those sections for the second or subsequent offense shall, unless the person is sentenced pursuant to the provisions of 2C:43-7, include a fixed minimum sentence of not less than 5 years during which the defendant shall not be eligible for parole. The court may not suspend or make any other non-custodial disposition of any person sentenced as a second or subsequent offender pursuant to this section. For the purpose of this section an offense is considered a second or subsequent offense, if the actor has at any time been convicted under sections 2C:14-2 or 2C:14-3a. or under any similar statute of the United States, this state, or any other state for an offense that is substantially equivalent to sections 2C:14-2 or 2C:14-3a.
N.J.S. § 2C:14-6