Quick answer: In Colorado, child support can be modified only for installments after the motion is filed, and only on a substantial and continuing change in circumstances. A recalculation under the guidelines that changes the monthly amount by less than 10% is deemed not substantial and continuing.
This Colorado child support modification calculator applies the test in C.R.S. 14-10-122. Enter your current order and the amount the guidelines give when you file (you can get it from the Colorado child support calculator) and it shows whether the 10% floor is met, the monthly difference and what it adds up to over the time a case takes. An order with no medical support provision can be modified on that ground alone, and a change of physical care has its own rule.
Colorado child support modification at a glance
| Rule | What Colorado says |
|---|---|
| Standard | Changed circumstances that are substantial and continuing, or an order with no medical support provision (C.R.S. 14-10-122(1)(a)) |
| 10% floor | A guideline change of less than 10% in the monthly amount is deemed not substantial and continuing (14-10-122(1)(b)) |
| Effective date | The filing date, unless undue hardship or substantial injustice; never earlier except after an agreed change of physical custody (14-10-122(1)(d)) |
| Accrued support | A payment is a final money judgment when due and unpaid and is not retroactively modified (14-10-122(1)(c)) |
| Change of physical care | Modified or terminated as of the date physical care changed; five-year limit unless substantially inequitable (14-10-122(5)) |
| Annual exchange | Parties exchange financial information once a year or less to update the order without a hearing (14-10-115(14)) |
How does child support modification work in Colorado?
- Know the standard and the 10% floor. See what counts as a substantial and continuing change in Colorado.
- File on time with the right forms. See how to modify child support in Colorado.
- Income problems. See reducing child support after job loss or incarceration in Colorado and, for what stays owed from before the filing, the Colorado child support arrears calculator.
What does this modification calculator check?
The calculator applies the 10% floor (a change of exactly 10% is not “less than ten percent”), the medical support ground and the physical-care rule, and shows the monthly and accrued difference. It cannot decide whether your change is substantial and continuing; that is for the court. Because the effective date is the filing date, the months before you file are the ones you cannot recover.
Frequently asked questions
How much does child support have to change to be modified in Colorado?
Applying the guidelines to the parties' circumstances at filing and getting a change of less than 10% in the monthly amount is deemed not a substantial and continuing change. You must still show a substantial and continuing change in circumstances.
Can I modify Colorado child support because the order has no medical support provision?
Yes. A decree can be modified on the ground that the order does not contain a provision on medical support, such as insurance coverage, deductibles and copayments or unreimbursed medical expenses.
From what date does a Colorado child support change take effect?
It should be effective as of the date of the filing of the motion, unless that would cause undue hardship or substantial injustice, and it may never be retroactive to before the filing date except after a mutually agreed change of physical custody.
Can Colorado change support that is already past due?
No. A support payment becomes a final money judgment when due and unpaid, and it is not retroactively modified, apart from the physical-care rule.
Can parents update Colorado child support without a hearing?
Yes. The parties exchange information once a year or less to update and modify the order without a court hearing; if they cannot agree, either party can move for a modification hearing.
Official sources
- C.R.S. 14-10-122: modification and termination of support
- C.R.S. 14-10-115: child support guidelines
- C.R.S. 14-10-122 (Colorado Public Law)
- Colorado Judicial Branch: Motion to Modify Child Support (JDF 1403)
- HB25-1159: Child Support Commission recommendations (signed)
- 42 U.S.C. 666(a)(9): no retroactive modification of support already due