Last verified: February 2026
Everything you need to know about New Hampshire child support laws, including the percentage-of-income formula, recent January 2025 updates, and when deviations from the guidelines apply.
Table of Contents
How to Apply for Child Support in New Hampshire
In New Hampshire, parents seeking child support must petition the court for an order. The Division of Child Support Services (DCSS) provides assistance with child support matters.
Contact Information:
- Main Line: (603) 271-6418
- Toll Free: 1-800-852-3345
- Locate family court offices by county
Services provided by DCSS:
- Locating absent parents
- Establishing paternity
- Establishing support orders
- Collecting and distributing payments
- Enforcing support orders
To apply, you will need the names and ages of the children, current addresses of both parents, information about any state aid received, and proof of paternity.
Parents receiving public assistance automatically receive child support services.
Establishing Paternity in New Hampshire
Before a child support order can be issued, paternity must be established. New Hampshire recognizes two methods:
- Voluntary acknowledgment: The father signs an affidavit attesting to paternity
- Judicial determination: Court-ordered genetic testing and legal determination
Contact DCSS or call 1-800-852-3345 to begin the paternity establishment process.
How Is Child Support Calculated in New Hampshire?
New Hampshire child support is governed by RSA Chapter 458-C. The guidelines use the parents’ combined monthly net income multiplied by percentage rates that vary by income level and number of children.
Determining Net Income
Gross income includes:
- Wages, salary, commissions, tips
- Bonuses and annuities
- Social Security benefits
- Trust income, lottery or gambling winnings
- Interest, dividends, investment income
- Net rental income, self-employment income
- Alimony received
- Pensions
- Workers’ compensation, unemployment, and disability benefits
Note: Regular overtime is excluded if earned at an hourly rate for hours over 40 per week in trades that traditionally pay overtime. Professionals and business owners cannot recharacterize income as overtime.
Adjusted gross income is calculated by subtracting:
- Court-ordered support actually paid to others
- 50% of self-employment tax paid
- Mandatory (not discretionary) retirement contributions
- Actual state income taxes paid
- Amounts paid for child care or medical support for the children in the case
Net income is the parents’ combined adjusted gross income less standard deductions for federal income tax, FICA, and Medicare.
The Child Support Formula
Under RSA 458-C:3, the total support obligation equals net income multiplied by the percentage from this table:
| Net Income | 1 Child | 2 Children | 3 Children | 4+ Children |
|---|---|---|---|---|
| $15,000 or less | 25.6% | 35.5% | 42.5% | 45% |
| $25,000 | 25% | 35% | 42% | 44.5% |
| $50,000 | 23% | 31.5% | 38% | 40.5% |
| $100,000 | 20% | 27.5% | 33% | 35.5% |
| $125,000 or more | 19% | 26% | 31% | 33.5% |
The NH Department of Health and Human Services publishes a detailed schedule with $1,000 increments and interpolated percentages.
Use the New Hampshire Child Support Calculator to estimate your obligation.
How Support Is Divided Between Parents
The total support obligation is divided between parents in proportion to their respective incomes. The obligor’s parental support obligation is their proportional share payable to the obligee.
Low-Income Provisions
If the obligor’s gross income is below the self-support reserve (130% of federal poverty guidelines for a single person), special provisions apply:
- If income is below the self-support reserve and the parent is not voluntarily unemployed, a minimum support order of $50/month may be issued
- If payment would reduce income below the self-support reserve, support is limited to the difference between income and the reserve (but not less than $50)
Medical Support Obligation
Under RSA 458-C:3(V), the presumptive medical support obligation is 4% of each parent’s gross income, unless the court finds this amount would be unjust or inappropriate.
Shared Parenting Adjustments (January 2025 Update)
The January 2025 amendments to RSA 458-C:5 added significant provisions for shared custody situations. Under Section 458-C:5(h):
Approximately Equal Parenting (Over 40% Each)
When parents:
- Each share 50% of child care costs, uninsured medical expenses, and extracurricular activities
- Have substantially similar incomes (within 10% of each other)
- Have an approximately equal parenting schedule (each over 40% of annual time)
There is a rebuttable presumption that $0 child support is appropriate.
Substantially Shared Parenting (Over 35% Each)
With substantially similar incomes and a substantially shared schedule (each over 35%), there is a rebuttable presumption that deviation from the guidelines is appropriate.
Unequal Incomes with Shared Time
When parents do not have similar incomes but do have shared custody, the court determines support based on the best interests of the children, focusing on whether the lower-earning parent can meet child-rearing costs in a similar style to the other parent.
Key rule: With shared or approximately equal parenting and no extraordinary circumstances, a child support order should not result in the obligee parent having higher adjusted monthly income than the obligor parent after adjustments.
How to Modify Child Support in New Hampshire
Under RSA 458-C:7, parents can request modification:
- Every three years without showing changed circumstances
- At any time with a substantial change in circumstances
Grounds for modification include:
- Changes in either parent’s income
- Incarceration or serious illness affecting earnings
- Involuntary job loss or pay cuts
- Changes in custody or parenting time
Download the NH Child Support Modification Kit.
Key Modification Rules
- Modifications are effective from the date notice was given to the respondent
- If modification results in overpayment, the court must order reimbursement (absent undue hardship)
- A new spouse’s income is not directly considered, but may be relevant if the parent is voluntarily unemployed
- Remarriage alone is not sufficient grounds for modification
Child Support Enforcement in New Hampshire
DCSS uses multiple enforcement tools for non-payment:
- License revocation: Driver’s, occupational, and professional licenses
- Credit bureau reporting: Impacts credit score and financing
- Tax refund interception: State, local, and federal
- Lottery and gambling winnings interception
- Passport denial or revocation
- Property liens: Remain until arrears are paid
Contempt of Court
If DCSS enforcement actions are unsuccessful, the receiving parent can petition for contempt charges. The paying parent must appear in court to explain the failure to pay.
If the court finds the failure willful, penalties may include fines, jail time, or payment of the other party’s attorney fees.
Criminal Penalties
Willful failure to pay child support in New Hampshire can be charged as:
- Class A misdemeanor: Up to 1 year in jail
- Class B felony: Up to 7 years in prison
Additional penalties may include probation, fines, or conditional discharge.
When Does Child Support End in New Hampshire?
Child support ends when the child:
- Turns 18, OR
- Graduates from high school (whichever is later)
Support Beyond Age 18
New Hampshire does not require parents to pay for college. However, if parents voluntarily agree to provide post-18 support in their agreement, the court will uphold that agreement.
Important: Read and understand any agreement before signing, as voluntary commitments become legally enforceable.
Termination of Parental Rights
Parents may voluntarily surrender parental rights, typically in adoption situations. This action:
- Is irreversible
- Ends the parent’s financial obligation going forward
- Does not eliminate existing child support arrears
Emancipation
New Hampshire does not have a formal emancipation statute. Minors seeking independence should consult with a family law attorney about their options.
Frequently Asked Questions
What is the minimum child support in New Hampshire?
The minimum support order is $50 per month, unless the court determines a lesser amount is appropriate based on the particular circumstances.
How is child support calculated with shared custody?
The 2025 amendments provide specific rules. With equal time and similar incomes, $0 support may be presumed. With unequal incomes, support is calculated to ensure the lower-earning parent can meet child-rearing costs in a comparable manner.
Is overtime included in income calculations?
Regular overtime in traditional hourly trades is excluded from gross income. However, professionals and business owners cannot recharacterize income as overtime wages.
Can incarceration be treated as voluntary unemployment?
No. Under RSA 458-C:2, incarceration cannot be considered voluntary unemployment.
Does a new spouse’s income affect child support?
Not directly. However, if a parent is voluntarily unemployed or underemployed, the spouse’s income may be imputed to the extent the parent previously earned.
How often can I request a review?
Every three years without showing changed circumstances, or at any time with a substantial change in circumstances.
More New Hampshire Laws