How Michigan Calculates Child Support: What Kalamazoo County Fathers Need to Know About the 2025 Formula, Income Sharing, and Expenses

Every month, the Friend of the Court calculates exactly how much you must pay or receive in child support. The 2025 formula changed the rules. If your current order doesn't account for the new medical expense threshold or childcare through age 13, you may be entitled to a recalculation.

Michigan uses a state-mandated formula to calculate child support. The result is called the guideline child support award. Courts must follow this formula unless there are compelling reasons to deviate.

• Both parents' net incomes
• Number of qualifying children
• Parenting time and overnights
• Health insurance premiums
• Out-of-pocket medical expenses
• Childcare costs

The 2025 Formula Changes

Michigan updated its child support formula effective January 1, 2025. The changes affect how courts calculate support amounts.

New Ordinary Medical Expense Threshold: $200 Per Child Per Year

Previously, the first $454 per child per year in ordinary medical expenses was built into the base support amount. Parents only split costs above that threshold.

Starting in 2025, that threshold dropped to $200 per child per year.

This means more out-of-pocket medical costs are now subject to sharing between parents.

• Old formula: You'd share only $146 ($600 minus $454)
• New formula: You'd share $400 ($600 minus $200)

That's a meaningful difference for families managing ongoing healthcare costs.

Childcare Expenses Extended to Age 13

Under previous guidelines, childcare expenses were typically factored into support calculations while children were younger.

The 2025 update extends childcare cost-sharing until the month a child turns 13.

This reflects the reality that many working parents need before- and after-school care, summer programs, and other supervision for children who aren't yet old enough to stay home alone.

If you're paying for childcare for a 10-, 11-, or 12-year-old, those costs can now be included in support calculations.

How Michigan Child Support Is Calculated

Understanding the formula helps you anticipate what a court might order—or whether your current order is still accurate.

Step 1: Determine Both Parents' Net Incomes

• Wages and salaries
• Bonuses and commissions
• Other earnings, minus taxes and certain deductions

Self-employment income, rental income, and investment returns may also be considered.

Step 2: Calculate Combined Net Income

Adding together each parent's monthly net income determines their combined net income.

The state uses this figure to set a base support obligation—how much parents are expected to spend on their children each month.

Step 3: Divide Proportionally Based on Income

Each parent is responsible for part of the base support obligation, proportional to their income.

For example, if you earn 70% of the combined net income, you are responsible for 70% of the base support obligation.

Step 4: Factor in Parenting Time and Overnights

The number of overnights each parent has affects the calculation.

More overnights with the non-custodial parent generally reduces the support amount, since that parent is directly covering more of the child's daily expenses.

• Jacob's net income: $4,200 per month
• Sarah's net income: $2,800 per month
• Jacob pays for health insurance
• No childcare costs

• Every other weekend schedule (73 overnights): $1,097 per month
• 70/30 schedule (109 overnights): $952 per month
• 60/40 schedule (146 overnights): $643 per month
• 50/50 schedule (182 overnights): $199 per month

The same parenting time change can save thousands of dollars annually.

Step 5: Add Healthcare and Childcare Costs

• Health insurance premiums for the children
• Out-of-pocket medical expenses above the $200 threshold
• Work-related childcare costs

These are added to the calculation and shared proportionally based on each parent's income.

Medical and Childcare Expenses Explained

Ordinary Medical Expenses

• Co-pays
• Prescriptions
• Over-the-counter medications

The $200 threshold applies to these costs. Courts may add amounts to cover higher expenses under the 2025 formula.

Childcare Expenses

• Before-school care
• After-school programs
• Summer camps
• Other supervision services

These costs are now included until the child turns 13.

When You Can Modify Child Support

A child support order isn't permanent. Under Michigan law, either parent can request a modification when circumstances change significantly.

Common Reasons to Seek Modification

1. Income changes: Job loss, promotion, career change, or retirement
2. Changes in parenting time: Significant shift in custody arrangement and overnights
3. Changes in childcare or medical expenses: Particularly relevant after 2025 updates
4. A child's changing needs: As children grow, their expenses change

You can request a review every three years, or sooner if there is a significant change.

How to Start a Modification Request

To modify support, you'll typically file a motion with the court that issued the original order.

The Friend of the Court office can also conduct reviews.

• Pay stubs
• Tax returns
• Childcare receipts
• Medical bills
• Parenting time records

Important: Informal agreements between parents don't modify a court order. If you and your co-parent agree to change the support amount, that agreement isn't enforceable until a court approves it.

Paying less than the ordered amount—even with the other parent's verbal okay—can result in arrears and enforcement actions.

Enforcing Child Support Orders

When a parent falls behind on child support, Michigan has several enforcement tools available. The Friend of the Court plays a central role in monitoring payments and pursuing collection.

Enforcement Options Include:

• Income withholding: Most child support orders automatically deduct payments from your paycheck
• Tax refund garnishment: The court can seize your state and federal tax refunds
• Property liens: Courts can place liens against your property or assets
• License suspension: Driving, hunting, professional, and other licenses can be denied or revoked
• Passport denial: The court can deny or revoke your passport

When unpaid support equals or exceeds one month's court-ordered payment, the Friend of the Court automatically begins enforcement proceedings.

Children Over 18

In most cases, Michigan law does not permit child support after the child reaches 18.

Exception: If the child is still in high school full-time and living with a parent at 18, support can continue until they turn 19 and a half.

The support order must state this clearly. Courts don't extend support past 19 and a half unless the parents agree in writing.

If a child graduates or drops out before then, support will end.

Using the Online Calculator

Michigan offers an online child support calculator through the Michigan Department of Health and Human Services.

While helpful for estimates, the calculator can't account for every nuance of your situation. For accurate numbers, especially in complex cases, working with an attorney ensures nothing is overlooked.

Deviations from the Formula

Courts typically follow the child support formula, but they can order different amounts when appropriate. This is called a deviation.

In 2025, the law made it clear that courts don't have to implement a deviation just because one applies. Judges can still consider it, but they can also look at other reasons that aren't on the official list.

• High childcare costs
• Support for stepchildren
• Parental medical conditions
• Children with special medical or schooling needs
• One parent supporting other children
• One parent who is incarcerated or otherwise unable to work

The court examines each case to determine whether the standard formula is effective or not. If not, the judge can adjust the support amount.

The Bottom Line

• The new $200 medical expense threshold
• Childcare costs through age 13
• The current income-sharing percentages

You may be entitled to a recalculation.

Either parent can request a modification when circumstances change significantly. To start, file a request with the Friend of the Court or the court itself.

Don't guess or estimate your overnights. The number will affect you, your children, and the other parent for years to come.