Ongoing child support can be modified, however, in New Jersey, arrears are not subject to modification except in cases where the child was legally subject to be emancipated and the non-custodial parent was late in filing a motion for emancipation. However, I do not believe the same applies when one child goes to live with the formerly non-custodial parent. That should have been the time to file a motion to modify your child support obligation going forward and have the judge recompute the numbers.
Answered on Sep 10th, 2017 at 8:22 AM