Utah Child Support Guidelines: How Support Is Calculated

Utah calculates child support using the income shares model: the court adds together both parents' gross incomes, looks up a base support obligation on a statutory table, and then splits that obligation between the parents in proportion to what each one earns. This is governed by the Utah Child Support Act, now found at Utah Code Title 81, Chapter 6. The Office of Recovery Services (ORS), Utah's state child-support agency, offers a free online Child Support Calculator and paper worksheets to estimate the amount — but only the ORS or a court can decide the final, binding number.

Where the child support law lives now

Time-sensitive: Utah's child support statutes were renumbered effective September 1, 2024. If you are looking at older forms, articles, or a decree that cites Title 78B, Chapter 12, that is the same law — it now lives at Title 81, Chapter 6. Keep this in mind if you're searching for a specific code section, since older citations may point to a section number that no longer matches the current numbering.

What counts as income

Under Utah Code § 81-6-203, gross income for child support purposes is broad. It includes both earned and unearned income, such as:

• Wages, salary, commissions, and bonuses
• Rents, dividends, and interest
• Pensions and capital gains
• Social Security benefits, workers' compensation, unemployment, and disability benefits
• Alimony received from a former spouse

One important limit: earned income (like wages) is generally counted only up to a 40-hour work week. Overtime and extra jobs beyond that baseline are treated differently, so if a parent regularly works more than 40 hours a week, it's worth confirming with your court or a legal-services resource how that additional income should be handled in your specific case.

The base obligation table depends on when your order was entered

Time-sensitive: Utah uses different statutory tables depending on the date of the support order:

• Orders entered before January 1, 2023 use the base combined obligation table at § 81-6-302 (with a low-income table at § 81-6-303).
• Orders entered on or after January 1, 2023 use the table at § 81-6-304 (with a low-income table at § 81-6-305).

This matters because the two tables can produce different base amounts for the same combined income. If you're comparing a worksheet from an old case to a new calculation, make sure you (or whoever is running the numbers) is using the table that matches your order's actual date.

Joint physical custody changes the math

Utah law defines joint physical custody, for child support purposes, as each parent having at least 111 overnights with the child per year (Utah Code §§ 81-6-206, 81-6-101). If both parents meet that overnight threshold, a different worksheet — the joint physical custody worksheet — applies, and it reduces the base combined obligation to reflect that both households are covering day-to-day costs.

According to the instructions for the joint physical custody worksheet, the reduction scales with overnights above 110:

• For 111 to 130 overnights, the base combined obligation is reduced by 0.27% (.0027) for each night above 110.
• At 131 or more overnights, the reduction rate rises to 0.84% (.0084) per qualifying night.

Because this calculation is sensitive to the exact overnight count, it's worth keeping your own calendar or parenting-time log if custody is close to the 111-night line — a handful of overnights can change which worksheet applies and how much the reduction is.

Modifying an existing child support order

Utah Code § 81-6-212 sets out two different paths for changing an existing order, and which one applies depends on timing:

• 3 or more years since the last order: a parent can file a motion to adjust if the guideline calculation now comes out 10% or more different from the current order, and that difference isn't temporary.
• Less than 3 years since the last order: a parent generally needs to file a petition to modify, showing a 15% or more difference from the guideline amount along with a substantial, material change in circumstances — the statute gives a 30% change in income as an example of that kind of change.

Time-sensitive / important: whichever route applies, a modification only changes support going forward. Under the federal Bradley Amendment (42 U.S.C. § 666(a)(9)(C)), child support that has already accrued cannot be reduced or forgiven retroactively — so if you're falling behind, don't wait to file, since the arrears keep building until a court actually changes the order.

How child support gets enforced

Utah's enforcement tools exist because federal law (Title IV-D of the Social Security Act, 42 U.S.C. §§ 654, 659, 666) requires every state to run a child-support enforcement agency and to adopt standard enforcement mechanisms. In Utah, that agency is the Office of Recovery Services (ORS). Federally required tools that ORS and Utah courts can use include:

• Income withholding directly from a paying parent's paycheck
• License suspension (driver's, professional, or recreational licenses)
• Liens against property
• Interception of federal tax refunds (42 U.S.C. § 664)

Federal law also waives sovereign immunity so that federal wages and benefits can be garnished to pay support (42 U.S.C. § 659). If a parent moves to another state, federal law (28 U.S.C. § 1738B) requires that other state to enforce Utah's order — and generally bars the new state from modifying it, so the order stays under Utah's continuing jurisdiction in most situations. Child support debt also follows a parent into bankruptcy: under 11 U.S.C. §§ 507 and 523, child support and alimony (as a "domestic support obligation") cannot be discharged in bankruptcy and are paid ahead of most other unsecured debts.

What you can do in Utah

1. Get an estimate first. Use the ORS online Child Support Calculator, or the paper worksheets, to get a ballpark figure. Remember: only ORS or a court sets the final, binding amount.
2. Gather income documentation for both parents — pay stubs, tax returns, and records of any other income sources listed under § 81-6-203.
3. Confirm your order date so you (or whoever is filing) uses the correct base obligation table — § 81-6-302/303 for pre-2023 orders, § 81-6-304/305 for orders from 2023 forward.
4. Track overnights carefully if custody is shared, since the 111-overnight threshold and the per-night reduction percentages can meaningfully change the worksheet result.
5. If you want to change an existing order, figure out how long it's been since the last order was entered — that determines whether you need a motion to adjust or a petition to modify, and what percentage difference you'll need to show.
6. If support isn't being paid, contact ORS about enforcement options rather than waiting, since past-due amounts generally can't be forgiven retroactively.
7. When in doubt, ask the court or a legal-services organization — ORS staff can help with case status and applications but cannot fill out or interpret these forms for you.

Key things that are easy to get wrong

• Citing the old "78B-12" numbering instead of the current Title 81, Chapter 6 (renumbered September 1, 2024).
• Using the wrong base obligation table because the order date wasn't checked against the January 1, 2023 dividing line.
• Assuming any custody split near 50/50 automatically counts as "joint physical custody" — it's specifically about hitting 111 or more overnights per year for each parent.
• Believing that a modification can erase support that has already accrued — it generally cannot.

This article is for general information only and is not legal advice; for guidance on your specific situation, contact the Utah courts' self-help resources, the Office of Recovery Services, or a licensed Utah attorney.