What Counts as a Substantial Change in Circumstances for Child Support in Wyoming
In Wyoming, child support can be modified on a 20% gap for an order over six months old, on any substantial change at any time, or on a three-year review. Changes run only from service of the petition.
What is a substantial change of circumstances for child support in Wyoming?
The statute does not define it; it lets any party seek a modification based on a substantial change of circumstances at any time (Wyo. Stat. 20-2-311(a)). It names one kind: the commencement of aid under the POWER program, Medicaid medical benefits, the supplemental nutrition assistance program or SSI is considered a substantial change requiring modification. The state judicial branch adds that changes in custody may also be enough, and that temporary changes in income likely will not (Wyoming Judicial Branch).
What is the 20% rule?
If the order was entered more than six months before the petition, or has not been adjusted within six months of filing, either parent can petition for review. The court applies the presumptive guideline; if support would change by 20% or more per month, it shall consider that a change of circumstances sufficient to modify (20-2-311(a)). Use the Wyoming child support modification calculator to test it.
| Existing monthly order | 20% higher | 20% lower |
|---|---|---|
| $200 | $240 | $160 |
| $500 | $600 | $400 |
| $800 | $960 | $640 |
| $1,500 | $1,800 | $1,200 |
With an $800 order, $1,000 is 25% higher and passes; $900 is 12.5% and does not.
What is the three-year review?
Every three years, on the request of either parent, or of the state agency if support rights are assigned, the court reviews the order, taking the child’s best interests into account, and adjusts it to the guidelines if appropriate, with no requirement to show a change in circumstances (20-2-311(a)).
How is net income worked out?
Net income is income from any source minus personal income taxes, social security deductions, dependent health coverage for all dependent children, actual payments on preexisting support orders for other children, other court-ordered support being paid and mandatory pension deductions; payments toward arrears cannot be deducted (Wyoming Judicial Branch; 20-2-303).
Is overtime counted?
Only if the court, after reviewing all overtime in the last 24 months, decides it is likely to continue (Wyoming Judicial Branch).
Does a custody change modify Wyoming support by itself?
No. If physical custody changes, support often changes too, but a court must issue a new custody order before the state agency or a lawyer can change the support amount; and support cannot be modified back to the date custody changed, so file with the court (Wyoming Judicial Branch).
Do agreed amounts matter in Wyoming?
Parents can agree on an amount only within the guidelines: the court compares it with the presumptive amount, and it cannot be lower if any child receives public assistance (Wyoming Judicial Branch; 20-2-307).
From what date can the order change?
An order for child support is not subject to retroactive modification except upon agreement of the parties, or for any period during which a petition for modification is pending, but only from the date notice of the petition was served on the other party (20-2-311(d)). Every month before service 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 Wyoming for the filing steps, and check what stays owed with the Wyoming arrears calculator.
Frequently asked questions
What is a substantial change in Wyoming child support?
Any substantial change in circumstances; starting POWER, Medicaid, SNAP or SSI is one.
Does exactly 20% count in Wyoming?
Yes. The statute says 20% or more per month.
Does a Wyoming custody change modify child support automatically?
No. A court must issue a new custody order, and support is not modified back to the change.
Can I modify Wyoming support more than once in six months?
A substantial change can be raised at any time; the 20% route needs an order over six months old.
Can Wyoming modify support that accrued before service?
No, except by agreement.
Official sources
- Wyo. Stat. 20-2-311: adjustment of child support orders
- Wyoming Judicial Branch: child support common questions
- Wyoming self-help packet: child support modification instructions
- 42 U.S.C. 666(a)(9): no retroactive modification of support already due
- 45 CFR 302.56: federal guideline requirements
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 Wyoming statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed Wyoming attorney.