What Counts as a Substantial Change in Circumstances for Child Support in New Hampshire

By the FigureMyTax Editorial Team · How we calculate

In New Hampshire, you can ask to modify child support at any time on a substantial change, or without one 3 years after the last order. A change can start only from the date notice of the petition was given.

What is a substantial change in circumstances for child support in New Hampshire?

The statutes we read do not define it. They say a parent may apply at any time for a modification based on a substantial change of circumstances (RSA 458-C:7, I(a)). Termination of support for one of several children under the age rules is a substantial change by statute (RSA 461-A:14, IV-a). Otherwise expect the court to look for a real and lasting change in income, the child’s needs or the parenting schedule.

Is there a percentage rule in New Hampshire?

Not in the statutes we read. The New Hampshire child support modification calculator therefore shows the gap and whether the 3-year route is open and does not give a pass or fail on a percentage.

For example, an $800 order against a $1,000 guideline amount is 25% lower than the guideline; within 3 years you would still have to show a substantial change.

What is the three-year route?

Three years after the entry of the last order for support, the obligor or obligee may apply for modification without the need to show a substantial change of circumstances (458-C:7, I(a)). The statute adds that this does not stop an application at any time on a substantial change. The department must tell parties it serves, at least every 3 years, of their right to request a review (458-C:7, I(b)).

Can a shared parenting schedule change support?

With similar incomes and an approximately equal schedule, where each parent pays half of child care, uninsured medical and agreed activities, there is a rebuttable presumption that a $0 obligation is appropriate (458-C:5, I(h)). Bring the schedule.

What does the New Hampshire court weigh when it recalculates?

Gross income from any source, with some exceptions, and special circumstances such as extraordinary medical, dental or education expenses, significantly high or low income, step-children and other children, parenting schedule and tax consequences (RSA 458-C:5; 458-C:2). A shared, equal parenting schedule with similar incomes carries a presumption of a $0 obligation or a deviation, under conditions.

Does a multi-child order step down automatically?

If the order covers more than one child and the court can determine that within the next 3 years support will end for one child under the age rules, it may state the new amount in the order, and it takes effect on the date or event without further legal action (461-A:14, IV-a). That makes the child’s aging out of the order a built-in change.

From what date can the order change?

Not before notice of the petition was given to the respondent (458-C:7, II). Every month before notice is lost:

Federal law also bars retroactive modification of support already due (42 U.S.C. 666(a)(9)).

What happens next?

Read how to modify child support in New Hampshire for the filing steps, and check what stays owed with the New Hampshire arrears calculator.

Frequently asked questions

Official sources

• RSA 458-C:7: modification of order
• RSA 461-A:14: support
• RSA 458-C:2: definitions, including gross income
• RSA 458-C:5: adjustments under special circumstances
• 42 U.S.C. 666(a)(9): no retroactive modification of support already due

This is general information, not legal advice. It is based on the cited New Hampshire statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed New Hampshire attorney.