South Carolina calculates child support using the "Income Shares" model: the court combines both parents' gross incomes, finds the basic support obligation on the state's guideline schedule, and then splits that amount between the parents in proportion to their share of the combined income. The result from the guideline worksheet is presumed to be the correct amount of support, though a parent can ask a court to deviate from it in specific situations. [S.C. Code Ann. § 63-17-470; S.C. Code Regs. ch. 114, art. 47]
How the Income Shares Model Works
The idea behind Income Shares is that a child should receive the same proportion of parental income that the child would have received if the parents lived together. To get there, South Carolina's Department of Social Services (DSS) publishes a guideline schedule that converts the parents' combined gross monthly income into a total basic support obligation. Each parent then owes a share of that total based on their percentage of the combined income. Because the guideline amount is presumed correct, a parent who wants a different number generally has to show the court why the guideline result would be unjust or inappropriate in that particular case. [S.C. Code Ann. § 63-17-470; S.C. Code Regs. ch. 114, art. 47]
The guideline schedule itself only calculates support directly for combined parental gross income up to $40,000 per month (about $480,000 per year). Above that combined-income level, the guidelines do not supply a fixed number, and the court decides the amount case-by-case. [SC DSS Child Support Guidelines (DSS Booklet 2819, Nov. 2024), II.A.3]
The Three Worksheets: A, B, and C
South Carolina's guidelines use three different worksheets depending on the custody arrangement:
Worksheet A — used in sole (primary) custody cases, where one parent has the child most of the time.
Worksheet B — used in split custody cases, where each parent has primary custody of at least one of the couple's children.
Worksheet C — used in shared physical custody cases, where both parents have substantial time with the child.
Overnights and the Shared-Custody (Worksheet C) Adjustment
Worksheet C — the shared-custody calculation — applies only when each parent has the child for more than 109 overnights per year, which is roughly 30% of the year, and both parents are expected to contribute directly to the child's day-to-day expenses during their own parenting time. Between roughly 110 and 128 overnights per year, the guidelines apply a graduated adjustment rather than a flat switch, so the support amount phases in rather than changing all at once at a single overnight threshold. [SC DSS Child Support Guidelines (DSS Booklet 2819, Nov. 2024), shared-custody section]
This is one of the more time-sensitive and fact-specific parts of the calculation — the exact overnight count in your custody schedule can change which worksheet applies and how much support is owed, so it is worth confirming the current overnight thresholds directly with the guidelines in effect when your case is calculated.
What Counts as Income
The guidelines calculate support from each parent's "gross income," which is defined broadly. It includes wages, salaries, commissions, bonuses, self-employment income, rental income, dividends, interest, pensions, Social Security benefits (but not SSI), workers' compensation, unemployment benefits, veterans' benefits, and alimony received. It excludes TANF (welfare) benefits, Supplemental Security Income (SSI), food stamps, the income of other people in the household, and in-kind income (non-cash benefits). If a parent is voluntarily unemployed or underemployed, the court can impute — that is, assign — a potential income figure to that parent rather than using their actual, lower reported income. [SC DSS Child Support Guidelines (DSS Booklet 2819, Nov. 2024), Gross Income definition]
Medical Expenses and Health Insurance
The basic guideline schedule already builds in an allowance of $250 per child per year for routine uninsured medical costs (things like over-the-counter medicine or minor doctor visit co-pays). Reasonable unreimbursed medical expenses above that $250-per-child-per-year figure are split between the parents in proportion to their share of the combined income, the same way the basic support obligation is split. Separately, the cost of the child's health-insurance premium and any work-related child care expenses are added into the support calculation on top of the basic obligation. [SC DSS Child Support Guidelines (DSS Booklet 2819, Nov. 2024), medical/health-insurance adjustments]
Low-Income Cases
If the parents' combined monthly gross income is under $750, the guideline schedule does not produce a standard number, and the amount is set case-by-case. In that situation, support is ordinarily not set below $100 per month, but the guidelines also direct the court to be careful not to set an amount that would deny the paying parent (the "obligor") the ability to meet their own basic subsistence needs. [SC DSS Child Support Guidelines (DSS Booklet 2819, Nov. 2024), II.A.2]
Periodic Review and Modification
Child support is not necessarily set in stone once ordered. For IV-D cases (cases where DSS's child support enforcement division is involved), DSS will review the order at least once every three years upon request and adjust it if the amount no longer matches the current guidelines — for example, after a significant change in either parent's income. [S.C. Code Regs. 114-4740 (Periodic Review); SC DSS Child Support Guidelines (DSS Booklet 2819, Nov. 2024)]
Enforcement: Why Support Orders Are Hard to Avoid
South Carolina's child support system operates inside a federal framework that requires every state to run a strong enforcement program. Federal law conditions funding on states adopting tools such as automatic income withholding from paychecks, paternity establishment, suspension of licenses, and liens against property for unpaid support, and it requires every state to maintain a child support enforcement (called "IV-D") agency. Federal law also waives the federal government's own immunity so that federal wages and benefits can be garnished to pay support. [42 U.S.C. §§ 654, 659, 666]
One particularly important federal rule: once child support has accrued (become due and unpaid), it generally cannot be reduced or forgiven retroactively — a court can change support going forward, but past-due amounts already owed typically survive that change. [Bradley Amendment, 42 U.S.C. § 666(a)(9)(C)] Unpaid support can also be collected by intercepting a parent's federal tax refund. [42 U.S.C. § 664]
If the Parents Live in Different States
When parents live in different states, federal law requires every state to enforce a child support order that was properly issued by another state, and it restricts other states from modifying that order except under narrow "continuing jurisdiction" rules. This is the federal backbone that works together with the states' own Uniform Interstate Family Support Act (UIFSA) rules to decide which state's order controls when a family has moved. [28 U.S.C. § 1738B]
Child Support and Bankruptcy
Child support (and alimony) are treated as "domestic support obligations" under federal bankruptcy law. That means they cannot be eliminated in bankruptcy and are paid ahead of most other unsecured debts if a bankruptcy estate has funds to distribute. Property-settlement debts owed to a former spouse under a divorce decree are also generally not wiped out in a typical Chapter 7 bankruptcy. [11 U.S.C. §§ 507(a)(1), 523(a)(5), 523(a)(15)]
What You Can Do in South Carolina
Gather income documentation for both parents — pay stubs, tax returns, self-employment records, and records of any other income listed above (Social Security, VA benefits, rental income, etc.).
Count actual overnights for the current or proposed custody schedule, since crossing the roughly 109-overnight mark can shift the calculation from Worksheet A to Worksheet C.
Get the current, official DSS guidelines and worksheets before estimating a number yourself — the schedule, income thresholds, and dollar figures are updated periodically, and the version cited here (the DSS guidelines booklet dated November 2024) may not be the version in effect when your case is calculated.
Identify health insurance and child-care costs so they can be added to the worksheet, and keep records of unreimbursed medical expenses if they may exceed the built-in per-child allowance.
If you are in a IV-D (DSS-involved) case and it has been about three years or your circumstances have changed significantly, ask DSS about a periodic review rather than assuming the original order is permanent.
This article is for general information only and is not legal advice; for your specific situation, consult South Carolina court resources or a professional licensed in South Carolina.
Frequently asked questions
How is child support calculated in South Carolina?
South Carolina uses the Income Shares model: the court combines both parents' gross monthly incomes, finds the basic support obligation on the DSS guideline schedule, and divides it between the parents based on their share of that combined income. The guideline amount is presumed correct unless a party shows the court a reason to deviate.
What counts as income for South Carolina child support?
Gross income includes wages, salaries, commissions, bonuses, self-employment income, rental income, dividends, interest, pensions, Social Security (not SSI), workers' compensation, unemployment, VA benefits, and alimony received. It excludes TANF, SSI, food stamps, other household members' income, and in-kind income.
How does shared custody affect South Carolina child support?
If each parent has the child for more than 109 overnights a year (about 30%) and both contribute to expenses, Worksheet C (the shared-custody worksheet) applies, with a graduated adjustment for overnight counts roughly between 110 and 128.
What happens to unpaid child support in South Carolina if the paying parent moves out of state?
Federal law requires every state to enforce a properly issued child support order from another state and limits other states from modifying it, working together with South Carolina's adoption of the Uniform Interstate Family Support Act (UIFSA).
Can child support be eliminated in bankruptcy?
No. Under federal bankruptcy law, child support and alimony are 'domestic support obligations' that cannot be discharged and are paid ahead of most other unsecured debts.
This article is general legal information, not legal advice, and may not reflect the most current law or the law in your jurisdiction. Laws vary by state and change over time. For advice about your specific situation, consult a licensed attorney.
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