Michigan calculates child support using a formula, not a fixed amount

Michigan does not have a set dollar amount for child support. Instead, the state uses a formula based on both parents' income, the number of children, and custody arrangement. The formula produces a number that a judge can order, but the actual amount you pay or receive depends on your specific situation — your income, your ex's income, how much time each parent spends with the child, and whether either parent pays for health insurance or childcare.

The formula itself is straightforward: it takes a percentage of combined parental income and divides it between parents based on how much each one earns. But "income" in Michigan includes wages, self-employment earnings, bonuses, rental income, and sometimes unemployment or disability benefits. What counts as income is often where disputes start.

A judge can order an amount different from the formula result if the formula would be unjust or inappropriate — for example, if one parent has the child 90 percent of the time, or if one parent earns far more than the other. These departures from the formula must be documented in writing with specific reasons.

Key Takeaways

  • Michigan's formula takes a percentage of combined parental income and splits it based on each parent's share of earnings, so the amount varies by how much both parents make.
  • The formula applies to combined parental income up to a cap that changes each year — in 2024 it was $163,000, but you should confirm the current year's figure with the Friend of the Court office.
  • Custody time matters: if one parent has the child significantly more than 50 percent of the time, the formula adjusts to account for that parent's higher costs.
  • A judge can order an amount different from the formula if following it would be unfair, but must explain the reason in writing.
  • The order stays in place until the child turns 18 or graduates high school, whichever is later, unless circumstances change enough to warrant a modification.

How the Michigan formula works step by step

The formula starts with combined parental income. Add both parents' gross income (before taxes). If either parent earns above the income cap — which the state adjusts yearly — only count income up to that cap. For 2024, the cap was $163,000 combined; confirm the current year's cap with your county's Friend of the Court office, as it changes annually.

Next, multiply combined income by a percentage based on the number of children. One child: 17 percent. Two children: 25 percent. Three children: 29 percent. Four children: 31 percent. Five or more children: 35 percent. This percentage reflects what the state estimates parents typically spend on child-related costs.

Then divide that amount between parents based on each parent's share of combined income. If one parent earns $40,000 and the other earns $60,000, the first parent pays 40 percent of the formula amount and the second pays 60 percent. The parent without primary custody (or with less custody time) pays their share to the other parent.

Finally, adjust for custody time. If both parents share custody roughly equally (45 percent or more each), the formula adjusts downward because both parents are directly spending money on the child. The more equal the split, the lower the payment. If one parent has the child 90 percent of the time, the formula does not adjust as much.

What counts as income for child support in Michigan

Michigan's definition of income is broad. It includes W-2 wages, self-employment income, bonuses, overtime, rental income, interest and dividend income, and income from trusts. It also includes unemployment benefits, workers' compensation, and disability benefits (both Social Security Disability and state disability payments).

Income does not include means-tested public benefits like TANF (Temporary Assistance for Needy Families), SSI (Supplemental Security Income), food assistance, or Medicaid. It also does not include child support or spousal support received from another relationship, or the value of non-cash benefits like housing or food provided by a third party.

If a parent is intentionally unemployed or underemployed — meaning they could earn more but choose not to — a judge can impute income, or assign an income level based on their education, work history, and job market. This prevents a parent from dodging support by quitting work or taking a lower-paying job.

How custody time affects the amount

Michigan recognizes that when both parents spend significant time with a child, both are paying for food, housing, utilities, and other costs. The formula accounts for this by reducing the payment obligation when custody is more equal.

If one parent has the child less than 10 percent of the time, the formula applies with no adjustment. If one parent has the child 10 to 45 percent of the time, the formula reduces the payer's obligation by a percentage that reflects the time spent. If both parents have the child 45 percent or more each, the reduction is larger.

The exact reduction depends on the specific percentages and is calculated using a formula within the formula. A parent with 30 percent custody time will see a smaller reduction than a parent with 45 percent custody time. If custody is truly 50-50, the payment obligation is significantly lower than if one parent has 70 percent.

When a judge can order a different amount

A judge is not required to follow the formula if doing so would be unjust or inappropriate. The law lists reasons a judge might depart from the formula: one parent has significantly more parenting time than the formula assumes, one parent has much higher income than the other, a child has special needs or extraordinary expenses, one parent is paying support for other children, or the parents' combined income is below the minimum threshold.

If a judge orders an amount different from the formula, they must write down the specific reason and the amount of the departure. This written explanation is important because it can be reviewed if either parent later asks to change the order.

A common example: if one parent has the child 85 percent of the time and the other parent has 15 percent, the formula might produce a certain number, but a judge might order less because the formula does not fully account for the large difference in parenting time and direct expenses.

How changes in income or custody affect the amount

A child support order does not automatically change when circumstances change. If your income increases, decreases, or if custody time shifts, either parent can ask the Friend of the Court (the county office that handles child support) to review the order and recommend a change.

Michigan law allows modification if there has been a substantial and continuing change in circumstances. A job loss, a significant raise, a move that changes custody time, or a change in health insurance costs can all trigger a review. The change usually needs to be significant enough to change the payment by at least 10 percent or $50 per month, whichever is greater.

The process starts with a written request to the Friend of the Court. They will gather income information from both parents and may recommend a new amount. If both parents agree, the judge can sign a new order quickly. If they disagree, a hearing is held and a judge decides.

When child support ends in Michigan

Child support continues until the child turns 18 and graduates from high school, or until age 19 if the child is still in high school. If a child is still enrolled in high school after turning 18, support continues through the end of that school year or until age 19, whichever comes first.

Support also ends if the child is emancipated (declared legally independent by a court), if the child joins the military, or if the child marries. In rare cases, a judge can order support to continue past 18 if the child has a disability or special needs.

The paying parent does not automatically stop paying when the child turns 18. The order must be formally closed by the Friend of the Court or by a judge. If you believe support should end, contact your county's Friend of the Court office with proof that the child has graduated or turned 19.

Frequently Asked Questions

Does Michigan child support include health insurance and childcare costs?

The formula amount does not include these separately — they are considered part of the percentage calculation. However, if one parent pays for the child's health insurance or childcare, that cost can be added to the formula amount. The parent paying these costs may receive a credit or the other parent may be ordered to reimburse a portion. This must be documented and included in the court order.

What if one parent makes much more money than the other?

The formula applies to combined income up to the yearly cap. Income above the cap is not automatically included in the formula calculation, but a judge can consider it when deciding whether to order an amount higher than the formula produces. A parent earning $500,000 per year might be ordered to pay more than the formula suggests, but the judge must explain why in writing.

Can child support be modified if I lose my job?

Yes. A job loss is a substantial change in circumstances. Contact the Friend of the Court and request a modification review. Bring proof of the job loss and your current income situation. If you are unemployed through no fault of your own, the amount may be reduced. If you quit intentionally, a judge may impute income based on your work history and earning potential.

How do I find out what the current income cap is?

Call your county's Friend of the Court office — the number is on the Michigan courts website under your county. They can tell you the current year's income cap and answer questions about how it applies to your situation. The cap is adjusted each year, usually in January.

What if the other parent refuses to pay what the judge ordered?

The Friend of the Court can enforce the order through wage garnishment, tax intercept, license suspension, or contempt of court proceedings. Report non-payment to the Friend of the Court office in writing with dates and amounts owed. They will investigate and take action on your behalf at no cost to you.