The multiplatinum-selling artist, whose real name is Jeffrey Atkins, admitted in March that he failed to pay taxes on more than $3 million that he earned between 2004 and 2006 while he lived in Saddle River.
Ja Rule was sentenced in New York City last month to up to two years in prison after he pleaded guilty to attempted criminal weapon possession. The case stemmed from a gun found in his car in 2007.
U.S. Magistrate Patty Shwartz in Newark ruled that the majority of his 28-month federal sentence could be served at the same time as New York state prison sentence.
Depending on his release date for his New York sentence, he could serve from four to 12 months of the federal sentence. The federal time will be served at the Oneida Correctional Facility in upstate New York, where he is serving the state sentence.
He has also been ordered to pay $1.1 million in unpaid taxes.
Wearing a bright yellow prison jumpsuit and handcuffed at the wrists, Ja Rule turned to look at his wife, who was seated in the courtroom, after the sentence was read. She declined to comment after the hearing, saying only that it was a stressful time.
Ja Rule's attorney, Stacy Richman, said he was saddened by the sentence, as he wanted to be reunited with his family and get back to work in order to be able to pay his taxes.