Michigan child support is calculated using the Michigan Child Support Formula (MCSF), which combines both parents’ net incomes, the number of children, and the number of overnights each child spends with each parent to produce a monthly dollar amount. That amount is presumptively correct, meaning a judge will order it unless a specific reason justifies going higher or lower.1Michigan Legislature. Michigan Compiled Laws 552.519 The formula’s aim is to reflect what both parents can actually afford to contribute.
What Counts as Income
Income is the biggest driver of the final number, and the formula defines it broadly. It includes wages, overtime, commissions, bonuses, and self-employment earnings. It also picks up unemployment and disability benefits, pensions and retirement distributions, Social Security payments, military pay and housing allowances, tips, royalties, dividends, and regular gambling or lottery winnings.2Michigan Courts. 2025 Michigan Child Support Formula Manual – Chapter 2 Determining Income
Non-cash benefits count too. Employer-provided housing, a company car, or meals get added at market value, and so do expense reimbursements that exceed what the parent actually spent. The manual’s goal is to measure how much money a parent genuinely has available for support, not just what shows up on a paycheck.2Michigan Courts. 2025 Michigan Child Support Formula Manual – Chapter 2 Determining Income
Courts verify income through tax returns, pay stubs, W-2s, and employer statements. When a parent is voluntarily unemployed or working below their capacity, the court can impute income based on that parent’s education, skills, and the local job market. That prevents a parent from lowering the obligation by choosing not to work or taking a lower-paying job without good reason.3State Court Administrative Office. 2025 Michigan Child Support Formula Manual
Turning Two Incomes Into One Obligation
Once each parent’s net income is established, the formula combines the two figures to estimate what the family would spend on the children in an intact household. Each parent’s share of that total obligation tracks their share of combined income. A parent earning 60 percent of the combined income is responsible for 60 percent of the support figure.
The Parenting Time Offset
Overnights matter. The more nights a child spends with a parent, the more that parent is already covering routine costs like food and utilities, so their cash obligation shrinks. The formula applies a parenting time offset that reflects those direct expenses, which is why two families with identical incomes can end up with very different support amounts depending on the schedule.3State Court Administrative Office. 2025 Michigan Child Support Formula Manual
Health Insurance and Childcare
Health insurance premiums for the children are split between parents in proportion to their share of combined income. The formula also gives guidelines on which parent should carry coverage and what counts as a reasonable premium. Work-related childcare expenses are divided the same way, so the cost of keeping both parents employed doesn’t land entirely on one side.3State Court Administrative Office. 2025 Michigan Child Support Formula Manual
Ordinary Medical Expenses
The base support amount already includes a built-in allowance for routine out-of-pocket medical costs like co-pays, prescriptions, and over-the-counter medication. That allowance is $200 per child per year: $400 for two children, $600 for three, and up to $1,000 for five or more. The parent receiving support gets a monthly advance toward those costs as part of the base amount.4Michigan Courts. 2025 Michigan Child Support Formula Supplement
Uninsured medical costs above that threshold are split in proportion to income. If one parent’s share of combined income is 65 percent and a child accumulates $500 in uninsured medical bills in a year, the first $200 is already covered in base support and the remaining $300 gets divided 65/35.3State Court Administrative Office. 2025 Michigan Child Support Formula Manual
When a Judge Orders a Different Amount
The formula’s output is presumptively correct, but a court can deviate when applying it would be unjust or inappropriate for a particular family. The MCSF manual lists deviation factors, though the list is not exhaustive. Common ones include:3State Court Administrative Office. 2025 Michigan Child Support Formula Manual
- A child with extraordinary or ongoing healthcare costs beyond the ordinary medical allowance.
- A parent who holds substantial wealth not reflected in current income, such as large investment accounts or inherited property.
- A parent already paying support for children from another relationship.
- A paying parent who is still a minor with limited earning capacity.
A deviation isn’t automatic just because one of these factors exists. The judge has to decide the factor warrants a different amount and explain the reasoning on the record.
Who Does the Calculation and How to Push Back
Michigan’s child support system runs through the Friend of the Court (FOC), an office attached to each county’s circuit court. The FOC investigates each family’s financial situation, applies the formula, and prepares a written recommendation for the judge. The judge isn’t required to follow it but usually does.
If you disagree with the FOC’s recommendation, you have 21 days from the date you’re served to file a written objection and request a hearing. Miss that deadline and the recommendation typically becomes a court order without further review. At the hearing you can challenge the income figures, the parenting time count, the treatment of insurance and childcare costs, or any other input the FOC used.
How Long the Number Lasts, and When It Can Be Recalculated
A support order isn’t permanent. Either parent can ask the court to recalculate by filing a Motion Regarding Support (Form FOC 50), and either parent can request a review through the FOC.5Michigan Courts. Motion Regarding Support – FOC 50 The FOC is not required to act on more than one request from the same parent every 36 months, though it will act sooner if a genuine change in circumstances warrants it. Cases involving public assistance or medical assistance are automatically reviewed at least every 36 months.6Michigan Legislature. Michigan Compiled Laws 552.517 – Review of Child Support
A modification requires showing that the recalculated amount differs from the current order by at least the threshold set in the MCSF; the statute delegates the exact figure to the formula rather than fixing a number.6Michigan Legislature. Michigan Compiled Laws 552.517 – Review of Child Support Common triggers include a significant income change for either parent, a shift in the parenting time schedule, or new healthcare needs for the child. Until a new order is signed, the existing one stays in effect and must be paid in full.
Support generally ends when the child turns 18, and it can continue up to age 19 and a half if the child is attending high school full-time, has a reasonable expectation of graduating, and lives full-time with the parent receiving support or in an institution.7Michigan Supreme Court. Administrative Memorandum 2012-07 Any unpaid balance that built up before the child aged out survives and remains collectible.