Maryland calculates child support using the income shares model set out in Md. Code, Family Law Title 12, Subtitle 2. The court adds both parents’ incomes together, adjusts for certain deductions, looks up the combined figure on the state’s guidelines schedule, and then splits the resulting obligation between the parents based on each parent’s share of that combined income. Which worksheet applies, Worksheet A or Worksheet B, depends mainly on how many overnights each parent has with the child during the year.
Before working through the formula, you can run your own numbers through our free Maryland child support calculator — no signup to get a quick, informal estimate. It won’t substitute for the worksheet a court actually files, but it gives you a starting number before you sit down with the official forms.
How the Maryland child support formula works
The guidelines calculation runs through a set sequence of steps. Courts follow this order under Family Law §§12-201 and 12-204:
- Determine each parent’s actual monthly income, or potential income if a parent is voluntarily impoverished.
- Calculate each parent’s adjusted actual income by subtracting pre-existing child support paid for other children, alimony actually paid, and an allowance for other children living in that parent’s home.
- Add both parents’ adjusted incomes together to get combined adjusted actual income.
- Look up that combined figure on the schedule in §12-204(e) to find the basic child support obligation.
- Add in the cost of the child’s health insurance premium, work-related child care, and any extraordinary medical expenses to reach the total obligation.
- Prorate the total obligation between the parents according to each parent’s percentage share of the combined income.
- Enter the numbers on Worksheet A (primary physical custody) or Worksheet B (shared physical custody), depending on the overnight schedule.
Illustrative example only. The figures below are rounded and simplified to show the sequence of steps, not to predict any outcome. They assume one child and a primary physical custody (Worksheet A) arrangement. Schedule amounts change with the number of children, and the add-on figures here are made up for the example. For an actual figure, use the current §12-204(e) schedule or the calculator linked above.
| Step | Illustrative figure |
|---|---|
| Parent A adjusted income | $5,000 |
| Parent B adjusted income | $3,000 |
| Combined adjusted income | $8,000 |
| Basic obligation, one child (schedule lookup) | ~$1,200 |
| Add-ons (insurance + child care), assumed | ~$400 |
| Total obligation | ~$1,600 |
| Parent A’s share (62.5% of combined income) | ~$1,000 |
| Parent B’s share (37.5% of combined income) | ~$600 |
In a Worksheet A case, the parent who does not have primary physical custody pays their prorated share to the other parent; the custodial parent is treated as spending their share directly on the child.
What counts as income under Maryland’s guidelines
Family Law §12-201 defines “actual income” broadly. It includes salary and wages, commissions, bonuses, dividend income, pension and annuity income, interest income, trust income, Social Security benefits, workers’ compensation benefits, unemployment insurance benefits, disability insurance benefits, and alimony or maintenance received, among other sources. It does not include means-tested public assistance such as Temporary Cash Assistance, Supplemental Nutrition Assistance Program (SNAP) benefits, or Supplemental Security Income.
If a parent has reduced their own income on purpose, without a reason beyond their control, the statute calls that “voluntary impoverishment.” In that situation, a court can calculate support using the parent’s potential income instead of actual income, based on factors like the parent’s employment history, education, skills, and the job market in their area. Under §12-204(b), a determination of potential income may not be made for a parent who is unable to work because of a physical or mental disability, who is caring for a child under the age of two for whom the parents are jointly and severally responsible, or who is incarcerated. The statute also provides that an incarcerated parent may not be considered voluntarily impoverished.
Adjustments and deductions built into the calculation
Before the combined income hits the schedule, each parent’s actual income is adjusted downward for:
- Pre-existing child support the parent actually pays for a different child.
- Alimony the parent actually pays.
- An allowance for support of another child living in that parent’s home, where the parent has a legal duty of support and the child is considered to spend more than 92 overnights a year in that home. This “multifamily adjustment” was added to §12-201(c) by legislation effective October 1, 2025. The allowance is calculated using only that parent’s own actual income and is then multiplied by 75%, and a court may decline to award it if doing so would be unjust after considering the best interest of the child whose support is being determined.
After the basic obligation is set, the guidelines add in the child’s health insurance premium, reasonable work-related child care, and extraordinary uninsured medical expenses, such as orthodontia or ongoing therapy. Those costs are divided between the parents in proportion to income, the same way the basic obligation is.
Shared physical custody and the 92-overnight rule
Maryland defines “shared physical custody” as an arrangement where each parent keeps the child overnight for more than 25% of the year — at least 92 overnights — and both parents contribute to the child’s expenses beyond the payment of support. That threshold was lowered from the previous standard of 35% (128 overnights) by Senate Bill 579 of the 2020 session, which took effect October 1, 2020 and applies only to cases filed on or after that date.
When both parents clear the 92-overnight line, the case uses Worksheet B instead of Worksheet A, and the math changes. Under §12-204(f) and (m), the basic obligation is first multiplied by one and one-half to produce an “adjusted basic child support obligation,” reflecting the duplicated household costs of two homes. That figure is divided between the parents in proportion to their adjusted actual incomes, each parent’s share is multiplied by the percentage of time the child spends with the other parent, and the two resulting amounts are offset so the parent owing the greater amount pays the difference.
Within that shared custody calculation, the statute adds a step for parents at the low end of the range. When a parent keeps the child for more than 25% but less than 30% of the year — at least 92 but not more than 109 overnights — that parent’s theoretical obligation is increased by a “shared physical custody adjustment,” a multiplier that steps down from 0.10 at 92 to 94 overnights to 0.02 at 106 to 109 overnights. This is a graduated adjustment inside Worksheet B, not an alternative to it; it was designed to smooth the sharp jump that used to occur at the threshold. If a parent has fewer than 92 overnights, Worksheet A applies and the shared custody rules do not.
Other states, including Arizona, also use income-shares formulas with their own custody thresholds and schedules; if you’re comparing jurisdictions, see our breakdown of how child support is calculated in Arizona.
When courts deviate from the guidelines, and what happens above $30,000 a month
Under §12-202, there is a rebuttable presumption that the guidelines amount is the correct amount. A parent asking the court to order a different amount has to show that applying the guidelines would be unjust or inappropriate in that specific case. In deciding that question, the court may consider financial considerations it deems relevant to the child’s best interests, along with other factors the statute lists. If the court departs from the guidelines, it must state its reasons in writing or on the record.
The guidelines schedule covers combined monthly adjusted actual incomes up to $30,000, raised from a previous $15,000 ceiling. The revised schedule was enacted by Senate Bill 847 of the 2020 session; its effective date was later extended by House Bill 1339 of the 2021 session to July 1, 2022, and it applies to cases filed on or after that date. Under §12-204(d), when combined adjusted actual income exceeds the highest level in the schedule, the court may use its discretion in setting the amount of support.
The same update also raised Maryland’s self-support reserve, an adjustment built into the low end of the schedule that protects a paying parent’s baseline income. Section 12-201(n) defines it as an adjustment ensuring that a support obligor keeps a minimum monthly income, after paying child support, federal and state income taxes, and Federal Insurance Contribution Act taxes, of at least 110% of the 2019 federal poverty level for an individual. That works out to roughly $1,145 a month; the statute states the percentage rather than the dollar figure. It is generally described as replacing an earlier reserve of about $867 a month, and it filled in obligation figures at very low income levels that previously had no listed number on the schedule.
The forms you’ll file
Maryland’s family courts use standardized forms for the guidelines calculation, available through the Maryland Judiciary’s family law forms page:
- CC-DR-034, Worksheet A — Child Support Obligation: Primary Physical Custody — used when one parent has primary physical custody (the other parent has fewer than 92 overnights a year).
- CC-DR-035, Worksheet B — Child Support Obligation: Shared Physical Custody — used when both parents clear the 92-overnight shared physical custody threshold.
- CC-DR-030, Financial Statement (Child Support Guidelines) — the shorter statement, generally used under Md. Rule 9-203(b) when child support is the issue and combined monthly income falls within the guidelines schedule.
- CC-DR-031, Financial Statement (General) — the longer statement, generally used when combined monthly income exceeds the top of the schedule, or in any case involving alimony.
Each parent typically completes their own financial statement, and the court or the parties use those figures to fill in the applicable worksheet.
How to modify a Maryland child support order
A Maryland child support order isn’t fixed forever. Under Family Law §12-104, a court may modify a support award after a motion for modification is filed and upon a showing of a material change of circumstance. Maryland courts generally look for a change that is substantial and relevant to the level of support, such as a significant, involuntary income change or a shift in the custody schedule. The statute also provides that if a party becomes incarcerated, the court may find a material change of circumstance where that party’s ability to pay is sufficiently reduced. The court may not retroactively modify a support award for any period before the date the motion was filed. Because the standard is fact-specific, it helps to gather documentation, such as pay stubs, tax returns, or a revised custody schedule, before filing.
Frequently asked questions
Do both parents’ incomes count toward Maryland child support?
Yes. Maryland’s income shares model combines both parents’ adjusted actual incomes to find the basic obligation, then divides that obligation between the parents based on each one’s share of the combined income.
What is the shared physical custody threshold in Maryland?
Shared physical custody applies when each parent keeps the child overnight for more than 25% of the year — at least 92 overnights — and both parents contribute to the child’s expenses. That threshold took effect October 1, 2020 and applies to cases filed on or after that date. Below the threshold, the case uses Worksheet A instead of Worksheet B.
Is there a cap on Maryland’s child support guidelines schedule?
The schedule in Family Law §12-204(e) covers combined monthly adjusted actual incomes up to $30,000. That schedule took effect July 1, 2022 and applies to cases filed on or after that date. Above the top of the schedule, §12-204(d) provides that the court may use its discretion in setting the amount of support.
What if the other parent is voluntarily unemployed or underemployed?
If a court finds a parent has voluntarily impoverished themselves, meaning they’ve freely chosen to have inadequate income for reasons within their control, the court can calculate support using that parent’s potential income instead of actual income, based on factors like work history, education, and local job availability. Potential income may not be imputed to a parent who is unable to work because of a physical or mental disability, who is caring for a child under age two for whom the parents are jointly and severally responsible, or who is incarcerated.
Which worksheet do I use, A or B?
Use Worksheet A (CC-DR-034) when one parent has primary physical custody. Use Worksheet B (CC-DR-035) when both parents have at least 92 overnights a year with the child, meeting Maryland’s shared physical custody threshold.
How do I change an existing Maryland child support order?
File a motion for modification and show the court a material change of circumstance, such as a substantial and involuntary income change or a shift in the custody schedule. Under §12-104(b), the court may not retroactively modify support for any period before the date the motion was filed.
If you want a quick estimate before you file anything, start with our free Maryland child support calculator — no signup required.
For a broader, plain-language walkthrough of how support cases unfold from filing through modification, the book Navigating Child Support covers the process in more depth.
Sources
- Md. Code, Family Law Title 12, Subtitle 2 (Child Support Guidelines), §§12-201–12-204: §12-201, §12-202, §12-204
- Md. Code, Family Law §12-104 (modification of child support award): §12-104
- Maryland General Assembly, Senate Bill 847 (Ch. 384, 2020 session; revised schedule to $30,000 combined monthly income and self-support reserve): SB 847 chapter text
- Maryland General Assembly, House Bill 1339 (2021 session; extended the effective date of the revised schedule from October 1, 2021 to July 1, 2022): HB 1339 bill page
- Maryland General Assembly, Senate Bill 579 (Ch. 143, 2020 session; shared physical custody 92-overnight threshold and shared physical custody adjustment, effective October 1, 2020): SB 579 chapter text
- Maryland Department of Human Services, Child Support Administration, Multifamily Adjustment Law Changes (HB 275 / SB 1038, effective October 1, 2025): multifamily adjustment overview
- Maryland Department of Human Services, Child Support Administration, 2022 Guidelines Quadrennial Review Case Level Report: report PDF
- Maryland Department of Human Services, Child Support Administration: dhs.maryland.gov/child-support-services
- Maryland Judiciary, Family Law Forms (CC-DR-030, CC-DR-031, CC-DR-034, CC-DR-035): mdcourts.gov/family/forms
- The Maryland People’s Law Library (Thurgood Marshall State Law Library, a Maryland Judiciary agency), “Calculating Child Support”: peoples-law.org/calculating-child-support
- The Maryland People’s Law Library, “Modifying Child Support”: peoples-law.org/modifying-child-support
This article is educational information only and is not legal advice. Maryland child support law changes over time, and every case involves its own facts. For guidance on your specific situation, consult a licensed Maryland attorney or your local circuit court’s self-help center.
