How is child support calculated in Michigan?

Using the Michigan Child Support Formula (MCSF), an income shares model under MCL § 552.605: both parents' net incomes are combined to determine the total support obligation, and each parent owes a percentage of that total equal to their share of the combined income.

What counts as net income for the MCSF?

Gross income minus federal and state taxes, FICA, mandatory retirement contributions, and existing support obligations for other children, the base figure used to combine both parents' incomes.

What changed in the 2025 formula update?

A 2025 change eliminated the old rule capping each parent's apportionment between 10% and 90%, so shares now track actual earnings precisely rather than being artificially bounded. The Friend of the Court Bureau also reworked the General Care Support Table and the parenting-time offset using more recent wage and cost-of-living data.

How is child support enforced in Michigan?

Through the Friend of the Court, which must begin enforcement action under Title IV-D once support at least equal to one month's payment becomes past due. Tools include mandatory income withholding on all new and modified orders, license suspension for arrears of two or more months, tax refund interception, and potential felony charges for nonpayment.

Michigan, United States

Michigan Child Support: A Parent's Guide

Q: How do I request a modification in Michigan?

Two paths: a Friend of the Court (FOC) review, generally simpler and less expensive, or a formal court motion. Cases are eligible for modification every 3 years at either party's request, or any time there's a change in circumstances, up until the child turns 18 (or 19.5 if still in high school).

How child support works in Michigan, in plain English: the Michigan Child Support Formula, modification, and Friend of the Court enforcement.

Legal sources reviewed: August 10, 2026

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In short: Michigan uses the Michigan Child Support Formula (MCSF), an income shares model recently updated in 2025 to remove the old apportionment caps and refresh its underlying data. Modification is available every 3 years or anytime circumstances change, and the Friend of the Court handles both review and enforcement, including mandatory income withholding.

This is an educational overview written for parents, not lawyers. It isn't legal advice. For anything beyond general understanding, talk to a licensed Michigan family law attorney.

What Michigan generally provides

Under MCL § 552.605, Michigan uses the Michigan Child Support Formula (MCSF), an income shares model combining both parents' net incomes to determine the total support obligation, based on the idea that children should receive the same portion of their parents' combined income as they would if the parents lived together.

Important terminology

MCSF: the Michigan Child Support Formula, the state's income shares calculation method.
Friend of the Court (FOC): the county-level office responsible for support review, modification recommendations, and enforcement.
General Care Support Table: the underlying guideline table the FOC Bureau reworked in the 2025 formula update.

How the calculation works

The court combines both parents' incomes to calculate a total support amount, then assigns each parent a share based on how much they contribute to that total. Net income starts from gross income minus federal and state taxes, FICA, mandatory retirement contributions, and any existing support obligations.

The 2025 formula update

A 2025 change eliminated the old 10%–90% apportionment cap, so each parent's share now tracks their actual earnings precisely rather than being artificially bounded at either end. The Friend of the Court Bureau also reworked both the General Care Support Table and the parenting-time offset, drawing on the last four years of wage and cost-of-living data.

What else factors in

Beyond net income and the number of children, the MCSF considers the number of overnights each parent has and specific add-on costs like health insurance and childcare.

Requesting or defending a modification

Michigan offers two paths: a Friend of the Court (FOC) review, generally simpler and less expensive, or a formal court motion. Cases are eligible for modification every 3 years at either parent's request, or anytime there's a change in circumstances. A court can change the support amount any time until the child turns 18, or up to 19½ if the child is still in high school. See the child support calculator and guideline finder for jurisdiction-specific calculation sources and guidance.

How enforcement works

The Friend of the Court enforces support orders, and under Title IV-D of the Social Security Act, it must begin enforcement action once support equal to or greater than one month's payment becomes past due. Income withholding is required on all new and modified orders unless both parents and the court agree to another payment method, and it can collect both current support and arrears. Beyond withholding, the FOC can suspend professional, sporting, recreational, and driver's licenses for arrears of two or more months, intercept state and federal tax refunds, and in Michigan, nonpayment can rise to a felony.

Common questions

Did the 2025 update change how much I owe? Possibly. Because the old apportionment cap is gone and the underlying data was refreshed, an order calculated before 2025 may no longer reflect the current formula, worth running a fresh calculation or FOC review if your order is older.

Is the FOC review or a court motion faster? The FOC review path is generally simpler and less expensive, but a formal court motion may be necessary for more complex or contested modifications.

What if my co-parent isn't paying? Contact your county's Friend of the Court, which is required to act once a full month's support is past due, pursuing income withholding, license suspension, and other tools.

Practical considerations

Because the 2025 formula change removed the old apportionment bounds, a large income gap between parents now translates more directly into the support split than it did under the prior cap, worth understanding before assuming an old estimate still applies, and confirming with the Friend of the Court or a Michigan family law attorney. For the custody rules that shape the parenting-time inputs to this formula, see the Michigan custody guide.

Official Michigan resources

FAQ

Questions, answered

This information is provided for educational purposes only and is not legal advice. Family law varies by individual circumstances and may change over time. Consult a qualified attorney or appropriate official resource for advice about your situation.