How is Child Support Calculated in North Carolina?

North Carolina calculates child support using both parents' gross incomes and three distinct worksheets — one for each type of custody arrangement. Which worksheet applies depends on how many overnights the non-custodial parent has with the child. Worksheet A covers primary custody arrangements. Worksheet B applies when the non-custodial parent has at least 123 overnights per year. Worksheet C handles split custody, where each parent has primary custody of at least one child. The current guidelines and remain in force through 2026.

The three-worksheet system — which one applies to you

Most states run child support through a single formula with adjustments for custody time. North Carolina uses a different structure: three separate worksheets, each designed for a fundamentally different custody arrangement. The worksheet you use shapes the entire calculation from the beginning.

Worksheet	Applies when	Key feature
Worksheet A — Primary	Non-custodial parent has fewer than 123 overnights/year	Standard proportional formula — non-custodial parent pays their income share of the basic obligation
Worksheet B — Shared	Non-custodial parent has 123 or more overnights/year	Combined income increased by 50%; each parent's obligation adjusted for time with the child
Worksheet C — Split	Each parent has primary custody of at least one child	Separate Worksheet A calculations run for each household; the difference is netted

For most families, the relevant question is whether the non-custodial parent's parenting time clears the 123-overnight threshold — the line between Worksheet A and Worksheet B. That threshold is lower than some states (Illinois uses 146 nights) but higher than others (Florida uses 73 nights).

Gross income — NC casts a wide net

North Carolina uses gross income — income before any deductions for taxes, FICA, health insurance, or retirement contributions. The definition is intentionally broad.

The only adjustments North Carolina allows before combining incomes are financial responsibility for natural or adopted children currently living with a parent (other than the children in this case) and existing child support obligations actually being paid for other children under a court order, written agreement, or voluntary arrangement.

Note what isn't deducted: taxes, health insurance premiums, and retirement contributions all stay in the gross income figure. This is the same approach as Ohio and Georgia — NC builds simplicity and consistency into the formula by using the wider pre-tax number.

Worksheet A — Primary custody

Worksheet A is the standard calculation when one parent has primary custody and the other has fewer than 123 overnights per year.

The process: both parents' adjusted gross incomes are combined, that total is matched to North Carolina's Basic Child Support Obligation schedule (which covers combined monthly gross incomes up to $40,000), and the non-custodial parent pays their income percentage of the scheduled amount. If the non-custodial parent earns 60% of the combined income, they pay 60% of the basic obligation.

Worksheet B — Shared custody (123+ overnights)

When the non-custodial parent has at least 123 overnights per year — roughly one-third of the year — North Carolina switches to Worksheet B. The calculation changes substantially.

Under Worksheet B, the combined income is increased by 50% before it's used to look up the schedule obligation. This multiplier — similar to Illinois's 1.5x factor — reflects the reality that two households are both actively spending on the child's daily needs. Each parent then contributes based on two things: their income percentage and the percentage of time the child spends with the other parent.

The 123-overnight threshold is a bright line. A parent with 122 overnights uses Worksheet A. A parent with 123 uses Worksheet B. For parents whose custody schedule falls near this threshold, the distinction is worth discussing carefully with a family law attorney, because the two worksheets can produce meaningfully different outcomes.

Worksheet C — Split custody

Split custody — where each parent has primary physical custody of at least one of the children — is handled through Worksheet C. This situation arises when, for example, one child lives primarily with one parent and another child lives primarily with the other.

Worksheet C runs a separate Worksheet A calculation for each household — determining what each parent would owe as the non-custodial parent for the child living with the other. The two obligations are then offset against each other, and the parent with the larger obligation pays the difference to the other parent.

Add-ons: health insurance and childcare

All three worksheets add specific expenses on top of the basic obligation and split them proportionally between the parents based on income.

Health insurance premiums for the children — the portion attributable to adding the children to an existing plan — are factored in and shared. Work-related childcare costs necessary for a parent to work or attend school are added and split. Extraordinary expenses for a child's special medical, educational, or other needs may also be addressed separately.

The self-support reserve

North Carolina protects lower-income paying parents through a self-support reserve of $1,299 per month. This is the minimum gross income a paying parent keeps after child support under the current guidelines.

If applying the standard formula would reduce the paying parent below this threshold, the obligation is adjusted. The reserve is higher than most other states we've covered — reflecting North Carolina's recognition that a support order that leaves the paying parent unable to meet basic living expenses doesn't serve anyone's long-term interests.

Deviation from the guidelines

North Carolina courts treat the guideline amount as the presumptive correct number. A deviation — upward or downward — requires a written finding that the guideline amount is not in the child's best interest. The court must document specifically what the guideline amount would have been and why a different amount is more appropriate.

Factors courts may consider for deviation include a child's special medical or educational needs, travel expenses related to the custody arrangement when parents live far apart, a child's independent income or assets, and any other circumstances the court finds relevant. The party seeking the deviation bears the burden of demonstrating why the guidelines result is inappropriate for this particular family.

If you're navigating divorce finances in North Carolina more broadly, our North Carolina divorce finances overview covers property division, alimony, and retirement accounts. We also have a dedicated guide on how alimony is calculated in North Carolina — including the dependent/supporting spouse framework and the illicit sexual behavior bar that is unique to NC law.

Common questions about North Carolina child support

When does North Carolina child support end? Child support in North Carolina generally ends when the child turns 18. If the child is still enrolled in high school at 18, support typically continues through graduation or age 20, whichever comes first. Courts may extend support beyond 18 for a child with a disability that prevents self-support.

Can North Carolina child support be modified? Yes. Either parent may seek a modification if there's been a substantial change in circumstances — typically defined as a change that would produce a support obligation at least 15% different from the current order. The change must be continuing and substantial, not temporary. Either parent may also request a review every three years under the three-year administrative review process.

What if a parent is self-employed? Self-employment income is included in gross income. North Carolina courts look at business revenue minus legitimate ordinary and necessary business expenses to determine net self-employment income. Expenses that appear personal, inflated, or unsubstantiated may be questioned. Courts have authority to examine tax returns and business records when self-employment income is disputed.

What if a parent is voluntarily unemployed? If a parent is voluntarily unemployed or working below their capacity, North Carolina courts may impute income — assigning earnings based on what the parent could reasonably earn given their education, work history, and the local job market. A court may also consider whether a parent's reduced income is temporary or a long-term change when determining whether imputation is appropriate.