Child Support with 50/50 Custody in South Dakota (2026 Guide)

In South Dakota, you usually still pay child support with 50/50 custody. The higher-earning parent owes the difference because the state uses an Income Shares Model under S.D. Codified Laws § 25-7-6.2. When each parent has at least 180 overnights per year, the court may apply a shared-parenting cross-credit under S.D. Codified Laws § 25-7-6.27 that reduces, but rarely eliminates, the obligation.

Key Facts: Child Support and 50/50 Custody in South Dakota

Do You Still Pay Child Support with 50/50 Custody in South Dakota?

Yes. In South Dakota, the higher-earning parent usually still pays child support with 50/50 custody. Under S.D. Codified Laws § 25-7-6.2, child support depends on each parent's income share, not parenting time alone. Equal time reduces the obligation through the cross-credit but rarely zeroes it out when incomes differ.

This surprises many parents. They assume that splitting parenting time 50/50 means neither parent pays the other. South Dakota law rejects that assumption. The Income Shares Model first asks what both parents together would spend on the child if they still shared one household, then divides that figure in proportion to each parent's net income. A parent earning 65% of the combined income is expected to cover 65% of the child's costs. Equal overnights do not change that expectation; they only change how directly each parent spends on the child. The shared-parenting cross-credit in S.D. Codified Laws § 25-7-6.27 adjusts for those direct expenditures, but the income gap usually leaves a residual payment from the higher earner to the lower earner.

How South Dakota Calculates Child Support with Equal Custody

South Dakota calculates child support by combining both parents' monthly net incomes, finding the base obligation on the statutory schedule in S.D. Codified Laws § 25-7-6.2, and dividing it by income share. For one child, the base obligation ranges from $254 per month at $1,200 combined monthly net income to $1,822 per month at $20,000 combined monthly net income.

The process runs in defined steps. First, each parent's gross income is reduced to net income under S.D. Codified Laws § 25-7-6.3 by subtracting federal income tax, Social Security and Medicare (FICA), mandatory retirement contributions up to 10% of gross income, the child's health insurance premium, and existing court-ordered support for other children. Second, the two net incomes are combined. Third, the combined figure and the number of children are matched to the schedule to find the base obligation. Fourth, that obligation is split by each parent's percentage of the combined income. In a true 50/50 custody case, a fifth step applies the cross-credit under S.D. Codified Laws § 25-7-6.27, which multiplies the base obligation by 1.5 before reallocating it to reflect each household's direct costs.

The 180-Overnight Shared Parenting Cross-Credit

The shared-parenting cross-credit applies when a court order gives each parent at least 180 overnights per calendar year, which equals roughly 49% of the year. Under S.D. Codified Laws § 25-7-6.27, the court may grant a cross-credit that reduces the support obligation, but the credit is discretionary, not automatic, and requires a detailed written parenting plan.

The 180-overnight threshold is the gateway to the credit, and 50/50 parenting time (182.5 overnights each) easily clears it. The mechanics matter. The cross-credit multiplies the base obligation by 1.5, allocates each parent's proportional share of that increased figure, and then offsets the two amounts so that only the net difference is paid. Because the math is built on income percentages, two parents who each have 50% of the overnights but unequal incomes still produce a net transfer from the higher earner. The court will also weigh whether granting the credit would have a substantial negative effect on the child's standard of living; if reducing support would leave the child materially worse off in the lower-income household, the court can decline the credit even when the 180-overnight test is met. Practitioners use the Shared Parenting Cross Credit Worksheet published by the South Dakota Department of Social Services for these calculations.

Worked Example: 50/50 Custody Support in South Dakota

In a 50/50 custody case where one parent nets $5,000 per month and the other nets $3,000 per month, the higher earner typically still pays several hundred dollars monthly. The base obligation for one child at $8,000 combined net income is about $1,050, and the higher earner's 62.5% income share drives the result even after the cross-credit.

Here is how the numbers move. Without any shared-parenting adjustment, the parent earning $5,000 (62.5% of the $8,000 combined) would owe 62.5% of the $1,050 base obligation, or roughly $656 per month. Applying the S.D. Codified Laws § 25-7-6.27 cross-credit, the court multiplies the $1,050 base by 1.5 to get $1,575, allocates each parent's share ($984 for the higher earner, $591 for the lower earner), and offsets the two. The net payment from the higher-earning parent falls below the standard $656 figure, often into the $250–$450 range depending on add-ons, but it does not disappear. This illustrates the central rule: in equal-custody South Dakota cases, support tracks the income gap, and 50/50 parenting time shrinks rather than erases the obligation.

When Income Is Equal Under 50/50 Custody

When both parents earn the same net income and share custody 50/50, the shared-parenting cross-credit under S.D. Codified Laws § 25-7-6.27 can reduce the support obligation to zero or near zero. Equal incomes mean each parent's proportional share of the increased base obligation is identical, so the offset cancels most or all of the transfer.

This is the one common scenario where a 50/50 parent may pay little or nothing. If two parents each net $4,000 per month, each holds 50% of the combined income and 50% of the overnights, so the cross-credit allocates each an equal share of the 1.5x base obligation and the amounts offset evenly. Even here, the result is rarely a clean $0. Add-on expenses change the picture. Childcare costs are allocated under S.D. Codified Laws § 25-7-6.18, uninsured medical expenses are apportioned under S.D. Codified Laws § 25-7-6.16 (with the custodial parent absorbing the first $250 per year), and the parent who actually pays the health insurance premium receives a credit. The court may also allocate travel costs between homes under S.D. Codified Laws § 25-7-6.15. Those line items can leave a modest net obligation even between equal earners.

Net Income Deductions That Affect 50/50 Support

South Dakota determines net income under S.D. Codified Laws § 25-7-6.3 by subtracting specific deductions from gross income, and these deductions directly change the income-share percentages that drive 50/50 child support. Allowable deductions include federal income tax, FICA, Medicare, mandatory retirement up to 10% of gross, and the child's health insurance premium.

Because shared-custody support depends on each parent's percentage of combined net income, the deductions are not a side issue; they decide who pays and how much. A parent with large mandatory retirement contributions or who carries the child's health coverage will show a lower net income, shifting more of the obligation onto the other parent. The statute also presumes earning capacity. Under S.D. Codified Laws § 25-7-6.4, each parent is presumed capable of working at least 1,820 hours per year at South Dakota's minimum wage of $11.20 per hour, producing an imputed annual income of $20,384 for a voluntarily unemployed or underemployed parent, absent disability or qualifying incarceration. This prevents a 50/50 parent from avoiding support by quitting work, because the court can impute income to the minimum-wage floor when calculating the income shares.

Add-On Expenses in Shared Custody Cases

In South Dakota 50/50 custody cases, the court allocates add-on expenses separately from the base obligation, in proportion to each parent's income. Childcare (S.D. Codified Laws § 25-7-6.18), uninsured medical costs (S.D. Codified Laws § 25-7-6.16), and the health insurance premium are added on top of the calculated support figure.

These add-ons frequently determine whether a 50/50 parent pays anything at all. Consider work-related childcare costing $600 per month. If the parents split combined income 60/40, the higher earner is responsible for $360 of that childcare even when overnights are equal. Uninsured medical expenses follow the same proportional logic, with the custodial parent covering the first $250 per child per year before the split applies. The parent who pays the monthly health insurance premium for the child receives a dollar-for-dollar credit against their share. Courts can also deviate from the guideline amount under S.D. Codified Laws § 25-7-6.10 for documented factors such as extraordinary medical needs or educational costs above $5,000 per year, but any deviation requires specific written findings. In shared custody, the interaction between the cross-credit and these add-ons is where the final number is decided.

Modifying a 50/50 Custody Support Order

South Dakota allows modification of a child support order when there is a substantial change in circumstances or after three years have passed. A change in the parenting schedule that pushes a parent above or below the 180-overnight threshold can trigger reapplication or removal of the cross-credit under S.D. Codified Laws § 25-7-6.27.

Support orders are not permanent. If a 50/50 arrangement shifts, the support number can shift with it. A parent whose overnights drop below 180 may lose the cross-credit entirely, increasing the obligation; a parent who gains overnights past 180 may newly qualify for it. Income changes matter just as much. Because shared-custody support is built on income percentages, a raise, a job loss, or a new mandatory deduction recalculates each parent's share. The Department of Social Services can review existing orders, and either parent can petition the court. South Dakota's modification process generally requires showing that recalculating support under current figures would change the amount meaningfully, so minor income fluctuations alone may not justify reopening an order. Document the changed overnights, current pay, and any new add-on costs before filing.

Proposed 2026 Changes to South Dakota Child Support

The South Dakota Commission on Child Support submitted recommendations for the 2026 legislative session that could raise the self-support reserve from $871 to $1,148 and update the obligation schedule for inflation. These proposed changes were under review as of late 2025 and may not yet be enacted; verify the current figures before relying on them.

Several pending items could affect 50/50 custody calculations. The proposed self-support-reserve increase, tied to a modified federal poverty level, would protect more low-income obligated parents, because the current $871 figure is anchored to 2016 poverty guidelines. The Commission also weighed two schedule-adjustment options: applying Midwest-region inflation from July 2021 through March 2025, or combining that inflation with South Dakota income data realigned using 2023 Census figures. A separate proposal would set the age of emancipation at 19 to address students in alternative school programs. The Commission's final report was due to the Governor and legislature by December 31, 2025, for the 2026 session. Until any bill is signed into law, the operative figures remain the $871 reserve and the $11.20 minimum-wage imputation under S.D. Codified Laws § 25-7-6.4. Always confirm the latest numbers with the South Dakota Department of Social Services.