What Counts as a Substantial Change in Circumstances for Child Support in South Dakota

By the FigureMyTax Editorial Team · How we calculate

In South Dakota, child support modification needs a substantial change in circumstances if the petition is filed within three years of the order, and no change after three years. Payments already due cannot be modified.

What is a substantial change in circumstances for child support in South Dakota?

The statutes we read do not define it. They tie it to timing: for an order entered or modified after July 1, 1997, the order may be modified on a showing of a substantial change in circumstances if the petition is filed within three years of the date of the order, and may be modified without showing any change in circumstances if the petition is filed after three years (SDCL 25-7A-22).

Is there a percentage rule in South Dakota?

Not in the statutes we read, so the South Dakota child support modification calculator shows the gap and the timing route rather than a pass or fail percentage.

For example, an $800 order against a $1,000 schedule amount is 25% lower than the schedule. Within three years the court must find a substantial change; after three years the gap itself is enough to ask.

What changed for older South Dakota orders?

Orders for support entered and in effect before July 1, 2026 may be modified in accordance with the chapter without requiring a showing of a change in circumstances from the entry of the order (25-7-6.13). The same section says that if a parent incarcerated for more than 180 days is released, the obligation in effect at release continues until either parent files a petition. Ask a licensed South Dakota attorney how the amendment applies to your order.

Can the court depart from the schedule?

Yes. A written finding that applying the schedule would be unjust or inappropriate rebuts the presumption; the finding must state the amount the schedule would have required and why the order deviates, and the best interest of the child must be considered (25-7-6.29).

Is a 50-50 schedule treated differently?

If a custody order provides shared parenting, the court applies a shared parenting cross credit under 25-7-6.27, and the abatement cannot exceed that credit (25-7-6.27). Ask the referee which applies to your schedule.

Does more parenting time change support?

If the child lives with the obligor six or more nights a month under a custody order, the court may grant an abatement of 38% to 66% of the basic obligation for those nights, after weighing the custodial parent’s fixed costs and the obligor’s increased costs; the obligor must show those costs and repay the abatement if the extra time is not used (25-7-6.14).

From what date can the order change?

Payments that have become due, paid or unpaid, are not subject to modification, except those accruing in a period when a petition for modification is pending, and only from the date notice of the hearing has been given to the obligee, the obligor and other interested parties (25-7-7.3). Every month before notice is lost:

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 South Dakota for the filing steps, and check what stays owed with the South Dakota arrears calculator.

Frequently asked questions

Official sources

• SDCL 25-7A-22: petition for modification
• SDCL 25-7-6.13: modification of prior orders; release from incarceration
• SDCL 25-7-7.3: payments not subject to modification
• SDCL 25-7-6.29: written finding to deviate
• SDCL 25-7-6.14: abatement
• 42 U.S.C. 666(a)(9): no retroactive modification of support already due

This is general information, not legal advice. It is based on the cited South Dakota statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed South Dakota attorney.