New Hampshire Child Support Laws: Guidelines and Calculations
How to Apply for Child Support in New Hampshire
Parents seeking child support in New Hampshire must petition the court for a support order. The Division of Child Support Services (DCSS) within the Department of Health and Human Services provides assistance throughout the process.
Contact Information:
- Main Line: (603) 271-6418
- Toll Free: 1-800-852-3345
- Central Information Unit: (603) 271-4427
- 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
- Reviewing and adjusting existing 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 through DCSS.
Establishing Paternity in New Hampshire
Before a child support order can be issued, legal paternity must be established for children born to unmarried parents. New Hampshire recognizes two methods under state law:
- Voluntary acknowledgment: Both parents sign an affidavit of paternity, typically at the hospital when the child is born or afterward at a vital records office.
- Judicial determination: Either parent or DCSS petitions the court for a paternity order. The court may order genetic testing to confirm biological parentage.
If the father is married to the mother at the time of birth, New Hampshire law presumes he is the legal father. For unmarried parents, establishing paternity is a necessary first step before seeking a child support order.
Contact DCSS at 1-800-852-3345 to begin the paternity establishment process.
How Is Child Support Calculated in New Hampshire?
New Hampshire adopted an income shares model in 2013, replacing the older percentage-of-income approach. Under this model, child support is based on both parents' combined monthly net income, reflecting how the family would have allocated resources for the children if the parents still lived together. The guidelines are set forth in RSA Chapter 458-C.
Determining Net Income
Gross income includes (per RSA 458-C:2):
- 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 from a person not party to the current support order
- Pensions and retirement benefits
- 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 their income as overtime.
Adjusted gross income is calculated by subtracting:
- Court-ordered support actually paid for other children
- 50% of actual self-employment tax paid
- Mandatory (not voluntary) retirement contributions
- Actual state income taxes paid
- Amounts paid for child care or medical support for the children in the current case
Net income is the parents' combined adjusted gross income minus standard deductions published annually by the Department of Health and Human Services. These deductions are based on federal IRS withholding table amounts for federal income tax, FICA, and Medicare.
The Child Support Formula
Under RSA 458-C:3, the total support obligation equals the parents' combined net income multiplied by a percentage that varies based on income level and number of children. The table below summarizes the key guideline percentages:
| Combined Monthly 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 guideline schedule with $1,000 increments and interpolated percentages between these income levels.
Use the official New Hampshire Child Support Calculator to estimate your obligation. If the combined monthly adjusted gross income exceeds $226,009, contact the Central Information Unit at (603) 271-4427 or 1-800-852-3345 ext. 14427 for guidance.
How Support Is Divided Between Parents
The total child support obligation is divided between parents in proportion to their respective shares of combined income. The obligor's parental support obligation is the proportional share payable to the obligee parent.
For example, if one parent earns 60% of the combined income and the other parent earns 40%, the first parent would be responsible for 60% of the total child support obligation.
Low-Income Provisions
The January 2025 amendments raised the self-support reserve from 115% to 130% of the federal poverty guideline for a single person. For 2026, this translates to approximately $20,748 per year ($15,960 x 130%). Special provisions apply when the obligor's gross income falls below this threshold:
- If gross income is below the self-support reserve and the parent is not voluntarily unemployed or underemployed, a minimum support order of $50 per month may be issued.
- If paying the full guideline amount would reduce the obligor's income below the self-support reserve, support is limited to the difference between the obligor's income and the reserve, but not less than $50 per month.
- Under RSA 458-C:2, incarceration cannot be treated as voluntary unemployment.
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 unjust or inappropriate. This obligation covers the cost of maintaining health insurance for the children.
Shared Parenting Adjustments (January 2025 Update)
House Bill 1564 (HB 1564), effective January 1, 2025, added significant provisions to RSA 458-C:5 for shared custody situations. These amendments reflect the growing trend of shared parenting in New Hampshire.
Approximately Equal Parenting (Over 40% Each)
When parents meet all of the following conditions:
- Each parent shares 50% of child care costs, uninsured medical expenses, and extracurricular activities
- Parents have substantially similar incomes (the difference between gross monthly incomes is not greater than 10%)
- Parents have an approximately equal parenting schedule (each parent has more than 40% of annual parenting time)
There is a rebuttable presumption that $0 child support is appropriate. This means neither parent owes child support unless evidence shows this would be unjust.
Substantially Shared Parenting (Over 35% Each)
When parents have substantially similar incomes (within 10%) and a substantially shared parenting schedule (each parent has more than 35% of annual parenting time), there is a rebuttable presumption that deviation from the standard guidelines is appropriate. The court will consider the specific circumstances to set a fair amount.
Unequal Incomes with Shared Time
When parents do not have substantially similar incomes but do share custody, the court determines support based on the best interests of the children. The focus is on whether the lower-earning parent can meet child-rearing costs in a comparable manner to the higher-earning 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 a higher adjusted monthly income than the obligor parent after accounting for the support transfer.
How to Modify Child Support in New Hampshire
Under RSA 458-C:7, either parent may request a modification of their child support order:
- Every 3 years without showing a substantial change in circumstances
- At any time when a substantial change in circumstances exists
DCSS is required to notify both parents of their right to request a review at least once every 3 years.
Grounds for Modification
Common grounds for seeking a modification include:
- Significant increase or decrease in either parent's income
- Involuntary job loss, pay cuts, or disability
- Changes in custody or parenting time arrangements
- Changes in the child's needs (medical, educational)
- Changes in the cost of health insurance
- Incarceration or serious illness affecting earning capacity
Key Modification Rules
- Modifications take effect from the date notice was given to the respondent, not the date of the new order.
- If modification results in overpayment, the court must order reimbursement unless doing so would cause undue hardship.
- A new spouse's income is not directly factored into the calculation. However, the court may consider it if the parent is voluntarily unemployed or underemployed.
- Remarriage alone is not sufficient grounds for modification.
- For multiple-child orders, when one child ages out of support, the obligor must petition to modify the order. The termination of support for one child is not automatic because the total support amount must be recalculated for the remaining children.
Child Support Enforcement in New Hampshire
When a parent falls behind on child support payments, DCSS and the courts have multiple enforcement tools available:
Administrative Enforcement Actions
- Income withholding: Automatic wage deductions from the obligor's employer
- License revocation: Driver's licenses, occupational licenses, and professional licenses
- Credit bureau reporting: Delinquent support is reported to credit agencies, affecting credit scores
- Tax refund interception: State, local, and federal tax refunds can be intercepted
- Lottery and gambling winnings interception
- Passport denial or revocation: Available for arrears exceeding $2,500 under federal law
- Property liens: Filed against real and personal property, remaining in effect until arrears are paid
- Financial institution data match: Bank accounts can be identified and levied
Show Cause Hearings and Contempt
If administrative enforcement actions are unsuccessful, the receiving parent or DCSS can petition for a show cause hearing. The obligor must appear in court to explain the failure to pay.
If the court finds the failure to pay was willful, penalties may include fines, jail time, payment of the other party's attorney fees, or compulsory community service.
Criminal Penalties
Willful failure to pay child support in New Hampshire can result in criminal charges:
- Class A misdemeanor: Punishable by up to 1 year in jail and fines
- Class B felony: Punishable by up to 7 years in prison
Federal charges under the Deadbeat Parents Punishment Act (18 U.S.C. 228) may also apply if the obligor willfully fails to pay support for a child living in another state and the obligation has remained unpaid for more than 1 year or exceeds $5,000.
When Does Child Support End in New Hampshire?
Under RSA 461-A:14, child support obligations terminate when the child:
- Marries
- Becomes a member of the armed services
- Is emancipated by court order under RSA 461-B
- Reaches age 18
Extended Support for Full-Time Students (Effective July 1, 2025)
Under the amended RSA 461-A:14(IV), if a child is still a full-time student at a secondary school, elementary school, charter school, or home education program at age 18, child support continues until the child graduates or reaches 2 months past age 19, whichever comes first. At that point, all child support obligations, including educational support obligations, terminate automatically without further legal action.
Support for Children with Disabilities
If the parties have a child with disabilities, the court may initiate or continue child support after the child reaches age 18. However, no child support order for a child with disabilities that becomes effective after July 9, 2013, may continue beyond the child's 21st birthday.
College and Post-Secondary Education
New Hampshire does not require parents to pay for college or other post-secondary education. However, if parents voluntarily agree in writing to provide post-18 educational support, the court will enforce that agreement. Read and understand any agreement thoroughly before signing, as voluntary commitments become legally binding.
Emancipation
New Hampshire has an emancipation statute under RSA 461-B. A minor who is at least 16 years old may petition the court for emancipation. If granted, the emancipation order terminates the parents' child support obligation going forward. However, existing child support arrears remain enforceable.
More New Hampshire Laws
New Hampshire Child Support Calculator
Estimate your child support obligation under RSA § 458-C. This calculator provides a step-by-step breakdown with statute citations.
New Hampshire Child Support Calculator
This state uses the Income Shares model, which considers both parents' income to determine a combined obligation, then splits it proportionally.
Based on RSA § 458-C · Effective January 1, 2025
Enter income details to see your estimate
How New Hampshire Calculates Child Support
- •New Hampshire uses the Income Shares model under RSA § 458-C, combining both parents' adjusted gross incomes to determine the basic child support obligation.
- •The basic obligation is determined from the New Hampshire Child Support Guidelines schedule based on combined adjusted gross income and number of children, then divided proportionally between parents.
- •A parenting time adjustment applies when the obligor has 128 or more overnights per year (approximately 35% of annual time — the "substantially shared parenting" threshold per RSA § 458-C:2, VIII-c). A higher-tier "approximately equal parenting" adjustment applies at 40%+ (~146 nights).
- •Health insurance premiums for the children and work-related childcare costs are added to the basic obligation and divided proportionally between parents.
- •New Hampshire includes a self-support reserve to ensure the obligor retains sufficient income for basic living expenses, with adjustments for low-income obligors.
- •Courts may deviate from the guidelines upon a finding of special circumstances, including extraordinary medical expenses, significantly higher or lower income than the guidelines contemplate, or other factors the court deems relevant.
What Is the Average Child Support Payment in New Hampshire?
Estimated Average Monthly Payment
$1,147/month
Estimated Annual Total
$13,764/year
New Hampshire does not publish an official “average” child support payment. This estimate was calculated using the New Hampshire guideline formula above with median income data from the U.S. Census Bureau, American Community Survey (ACS) 2024 — New Hampshire Median Earnings. Your actual amount will differ — use the calculator above with your own numbers for a personalized estimate.
Assumptions used in this estimate
- •Obligor net monthly income of $4,000 (New Hampshire median full-time earnings after taxes, Census ACS 2024)
- •Obligee net monthly income of $3,200 (New Hampshire median female full-time earnings after taxes)
- •2 children
- •$200/month for children's health insurance
- •No childcare costs; 52 overnights/year with obligor (below parenting time adjustment threshold)
Data year: 2024
Important Legal Disclaimer
This calculator provides an estimate only based on New Hampshire's child support guidelines. Actual court-ordered amounts may differ based on factors not captured here, including special needs, shared custody arrangements, travel costs, and judicial discretion.
This is not legal advice. Consult a family law attorney for guidance specific to your situation.
Sources and References
- RSA Chapter 458-C: Child Support Guidelines(gc.nh.gov).gov
- RSA 458-C:2: Definitions (Income, Self-Support Reserve)(gc.nh.gov).gov
- RSA 458-C:3: Child Support Formula(gc.nh.gov).gov
- RSA 458-C:5: Adjustments Under Special Circumstances (Shared Parenting)(gc.nh.gov).gov
- RSA 458-C:7: Modification of Order(gc.nh.gov).gov
- RSA 461-A:14: Support (Termination Age and Conditions)(gc.nh.gov).gov
- NH Division of Child Support Services (DCSS)(dhhs.nh.gov).gov
- NH Child Support Guidelines and Calculator(dhhs.nh.gov).gov
- NH Child Support Enforcement(dhhs.nh.gov).gov
- New Hampshire Child Support Calculator(business.nh.gov).gov
- Federal Poverty Guidelines (HHS)(aspe.hhs.gov).gov