South Carolina combines both parents' gross incomes into one figure, looks up the result on a state guideline schedule, and splits the obligation between the parents based on their share of that combined income. Health insurance and work-related child care costs get added on top and divided the same way. The state updated its guideline schedule in January 2024 for the first time in a decade, raising support amounts across most income levels.
South Carolina's income shares calculation under S.C. Code § 63-17-470, what counts as income, the January 2024 guideline update and its $40,000-a-month cap, the $1,010.50 self-support reserve, a worked example, the shared custody worksheet that applies once a parent has more than 109 overnights a year, health insurance and child care add-ons, and how modification works.
South Carolina's income shares model: combine, then split
South Carolina uses an income shares model under S.C. Code § 63-17-470. The idea behind income shares is that a child should generally receive the same proportion of parental income they would have received if both parents lived in the same household. To get there, courts add both parents' gross monthly incomes together, then figure out what percentage of that combined total each parent contributes.
That combined-income approach is what separates South Carolina from a small number of states that apply a flat percentage to only the paying parent's income. In South Carolina, both parents' earnings are part of the calculation from the very first step, and both parents share responsibility for the basic obligation in proportion to what they earn.
The basic steps: schedule, split, add-ons
The calculation follows a consistent sequence built into South Carolina's Child Support Guidelines and its official worksheets.
| Step | What happens |
|---|---|
| 1. Determine gross income | Each parent's gross monthly income is established, with adjustments for existing support obligations to other children |
| 2. Combine incomes | Both parents' adjusted gross incomes are added together to get the combined monthly figure |
| 3. Find each parent's share | Each parent's income is divided by the combined total to get a percentage contribution |
| 4. Look up the basic obligation | The combined income and number of children are matched against the Schedule of Basic Child Support Obligations |
| 5. Split the basic obligation | Each parent's percentage share (step 3) is applied to the basic obligation (step 4) |
| 6. Add health insurance and child care | The paying parent's share of the child's health insurance premium and work-related child care costs is added to the basic amount |
This sequence produces the standard order under Worksheet A, used for sole or primary custody arrangements. Different worksheets apply for split custody (Worksheet B, where each parent has primary custody of at least one shared child) and shared physical custody (Worksheet C, covered further down).
What counts as income in South Carolina
South Carolina's guidelines define gross income broadly — most money coming in before taxes generally counts toward the calculation.
| Income type | Generally included? |
|---|---|
| Wages, salaries, commissions, bonuses, tips | Yes |
| Self-employment income | Yes — gross receipts minus ordinary business expenses |
| Pension, retirement, and Social Security income | Yes |
| Disability and workers' compensation payments | Yes |
| Alimony received from a prior relationship | Yes |
| Means-tested public assistance (SNAP, SSI, TANF) | Generally excluded |
If a parent is voluntarily unemployed or working well below their earning capacity without a reasonable justification, a court may impute income — assigning a figure based on employment history, education, and job opportunities in the area, rather than accepting a reduced paycheck at face value.
The 2024 update: a higher income ceiling
South Carolina's Department of Social Services updated the Child Support Guidelines effective January 15, 2024 — the first revision since 2014. The update raised the combined gross income cap on the guideline schedule from $30,000 a month to $40,000 a month, and adjusted support amounts across most income levels by roughly 25% or more to reflect a decade of inflation. For combined incomes above the $40,000 ceiling, courts have discretion to set support based on the child's needs and other factors rather than reading a number straight off the schedule.
The self-support reserve: protecting a minimum income
Before finalizing an obligation, South Carolina's guidelines apply a self-support reserve set at $1,010.50 a month. This reserve is meant to leave a lower-income paying parent enough to cover basic living costs after child support is paid. When a parent's income falls within the shaded, lower-income portion of the guideline schedule, courts may reduce the calculated obligation so it doesn't push that parent's remaining income below the reserve amount. Even with this protection, courts typically still order at least some minimum monthly support rather than reducing an obligation to zero.
Worked example — the basic calculation
This is a hypothetical example for illustration only. Use the child support calculator for an estimate based on your own numbers.
This is the basic figure before health insurance and child care are added under step 6. Those add-ons are divided in the same proportion — roughly 69/31 in this example.
Shared custody: when Worksheet C applies
South Carolina switches from the standard Worksheet A to the shared physical custody Worksheet C once a parent has court-ordered visitation with the children for more than 109 overnights a year — roughly 30% of the year. Worksheet C multiplies the basic obligation by 1.5 to account for the fact that each parent is maintaining a full household capable of housing the children, then divides that larger obligation proportionally, crediting each parent for the time they actually have the children.
When a parent's overnights fall between 109 and 128 a year, South Carolina doesn't switch abruptly from Worksheet A to Worksheet C. Instead, both worksheets are calculated, and the final order blends the two — the gap between the Worksheet A and Worksheet C amounts is scaled by how far into that 109-to-128 range the overnight count falls. Once a parent reaches 129 or more overnights, the full Worksheet C shared custody calculation applies. The court also has discretion to decide whether a shared custody adjustment is appropriate at all, based on whether it would negatively affect the children's standard of living.
Worked example — shared custody adjustment
Simplified for illustration. South Carolina's official worksheets apply exact rounding and credit rules.
Because Parent B has more than 129 overnights, the full Worksheet C calculation applies rather than the blended 109-to-128 formula. Each parent gets credit for the portion of the shared obligation they cover directly during their own parenting time, and the paying parent's final obligation is adjusted down accordingly.
Health insurance, medical expenses, and child care add-ons
The basic obligation covers everyday costs like housing, food, and clothing, and already builds in $250 per child per year for routine uninsured medical expenses such as co-pays and over-the-counter medicine. Reasonable and necessary medical costs beyond that $250 threshold — extraordinary medical expenses — are divided between the parents in proportion to their income share, at the court's discretion for what counts as reasonable and necessary. Whichever parent pays the premium for the children's health insurance generally receives a credit for the portion of that premium covering the children. Work-related child care costs are typically added to the total obligation and divided the same way, based on each parent's percentage of combined income.
For a broader look at how property and alimony are handled alongside child support, see the South Carolina divorce finances overview. We also have a companion guide on how alimony is calculated in South Carolina, including how adultery by the requesting spouse can bar a support award.
When can South Carolina child support be modified?
Either parent can ask a court to modify an existing order when there has been a substantial change in circumstances — a significant increase or decrease in either parent's income, a new custody or overnight schedule, a change in a child's medical or child care costs, or enough time passing since the last review. Informally reducing or skipping payments without a modified order is not a safe substitute for going back to court, since the original order generally stays enforceable until it's formally changed. For more on how the modification process typically works, see our general guide on child support modification.
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Common questions about South Carolina child support
How is child support calculated in South Carolina? South Carolina combines both parents' gross monthly incomes, looks up the combined obligation on the DSS Schedule of Basic Child Support Obligations, splits it based on each parent's income share, and then adds health insurance and work-related child care costs divided the same way. For a broader explanation of income shares versus other state models, see our general guide on how child support is calculated.
What is the self-support reserve and how does it protect low-income parents? It's a $1,010.50-a-month income floor built into the 2024 guidelines. When a paying parent's income falls into the lower, shaded portion of the schedule, courts may reduce the calculated support obligation so that parent still keeps enough income to cover basic living costs.
What counts as income for South Carolina child support? Wages, salaries, bonuses, self-employment income, pensions, disability payments, and most other regular income generally count. Means-tested public assistance is generally excluded, and a court may impute income to a parent who is voluntarily unemployed or underemployed.
Can South Carolina child support be modified? Yes, when there's been a substantial change in circumstances — a significant income change, a new custody schedule, or a change in a child's costs. The change generally needs to go through the court to be enforceable.
Educational purposes only. This article provides general information about how South Carolina child support is typically calculated and is not legal or financial advice. Every case is different and outcomes vary significantly based on specific circumstances, judicial discretion, local rules, and factors not captured here. Always consult a licensed family law attorney in South Carolina for advice specific to your situation.