What Counts as a Change in Circumstances for Child Support in Michigan
In Michigan, the friend of the court must petition to modify child support only if the formula amount differs by at least 10% or $50 a month, whichever is greater; a change can start only from notice of the petition.
What do you have to show to modify child support in Michigan?
The court modifies an order as the circumstances of the parents and the benefit of the children require, and every modification starts from the Michigan child support formula (MCL 552.605(2)). In practice a parent shows a change in circumstances since the last order, such as a change in income, parenting time, health insurance cost or the child’s needs. The friend of the court has its own list of reasonable grounds to start a review, including unordered changes in physical custody, increased or decreased need of the child, access to health coverage, changed coverage cost, changed financial conditions including unemployment compensation, and an order based on incorrect facts (MCL 552.517(1)(f)).
What is the 10% or $50 threshold?
On a review, the office must petition the court if modification is needed, unless the difference between the existing and projected award is less than the minimum threshold for modification established by the formula, or the previous deviation reasons remain unchanged (552.517(5)). The 2025 formula manual states the threshold as 10% of the current order or $50 a month, whichever is greater. The Michigan child support modification calculator tests it.
| Existing monthly order | Threshold | Formula amount at or above | or at or below |
|---|---|---|---|
| $200 | $50 | $250 | $150 |
| $500 | $50 | $550 | $450 |
| $800 | $80 | $880 | $720 |
| $1,500 | $150 | $1,650 | $1,350 |
With an $800 order the threshold is $80, so a formula amount of $1,000 (25% higher) meets it and $870 does not.
Does a new health insurance cost count?
Yes. A changed dependent health care coverage cost from the amount used in the previous order is one of the reasonable grounds for a friend of the court review (552.517(1)(f)(iv)). Bring the premium statement.
Can a smaller change still be modified in Michigan?
The threshold governs when the friend of the court must petition. A parent can still file their own petition and ask the judge to find a change in circumstances. Expect the court to ask whether the change is real and lasting.
Does the Michigan friend of the court review automatically?
Not for most orders. It must review at least every 36 months in cases with public assistance, and otherwise on written request of either party, within 14 days deciding whether the order is due, with no obligation to act on more than one request from a party every 36 months (552.517(1)). Once a review is required, it must obtain a modification within 180 days if appropriate (552.517(3)).
What if the order was a deviation?
If the court previously found the formula unjust or inappropriate and the office finds the facts and reasons for the deviation unchanged, the office need not petition (552.517(5)(b)). Deviations require written or on-the-record findings of the formula amount, how the order deviates and why (552.605(2)).
From what date can the order change?
Each payment is a judgment on and after its due date and is not subject to retroactive modification, except for a period when a petition for modification is pending, and only from the date notice of the petition was given (552.603(2)). Every month before notice is lost:
| Monthly difference | Lost after 6 months | Lost after 12 months |
|---|---|---|
| $100 a month | $600 | $1,200 |
| $200 a month | $1,200 | $2,400 |
| $400 a month | $2,400 | $4,800 |
Federal law also bars retroactive modification of support already due (42 U.S.C. 666(a)(9)).
What happens next?
Read how to modify child support in Michigan for the filing steps, and check what stays owed with the Michigan arrears calculator.
Frequently asked questions
What is the Michigan child support modification threshold?
10% of the current order or $50 a month, whichever is greater, before the friend of the court must petition.
Can I modify Michigan child support for a smaller change?
You can still file a petition and ask the court to find a change in circumstances.
How often does the Michigan friend of the court review support?
At least every 36 months in public assistance cases, and on request, with one request per party every 36 months.
Does Michigan allow retroactive child support modification?
Only from the date notice of the petition was given.
Are Michigan child support amounts monthly?
Yes. Orders are stated in monthly amounts payable on the first of each month.
Official sources
- MCL 552.603: support order as a judgment; no retroactive modification
- MCL 552.605: child support formula and deviation
- MCL 552.517: review of child support orders
- MCL 552.517b: review notice, objections and imputed income
- MCL 552.517f: abatement during incarceration
- 42 U.S.C. 666(a)(9): no retroactive modification of support already due
A local family law attorney can review your situation — many offer a free consultation.
This is general information, not legal advice. It is based on the cited Michigan statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed Michigan attorney.