A child support order amount may change through a cost-of-living adjustment (COLA) or a modification. Arrearages may also affect the monthly support payment.


Every child support order entered since 1983 must include a biennial COLA that is compounded. Orders entered before 1983 had to have a COLA added whenever an enforcement or modification action occurred in the case after 1983.

In all IV-D cases, the COLA takes effect the first of May of every other year after the support order is first entered or the COLA clause is added to an existing order. In non-IV-D cases, the COLA may take effect in any month, as long as it has been at least two years since the last adjustment. The court may use any cost-of-living indicator published by the U.S. Department of Labor it finds appropriate to determine the percentage change in the support amount. The obligor is given 20 days notice before the COLA takes effect. The obligor may ask for a court hearing to oppose a COLA on grounds that the obligor has had an insufficient increase in income. If the obligor timely files a motion contesting the COLA, the COLA will be stayed pending the outcome of a court hearing. The court may order that the COLA go into effect in whole or in part, or not at all. If the obligor does not oppose the change, it goes into effect automatically. Minn. Stat. § 518A.75.


The state must notify parents to IV-D cases every three years of the right to request a review of their cases to see if a modification is appropriate. In addition to the right to request a review every three years, any party in IV-D and non-IV-D cases, including the county, may request a review to see if a modification is appropriate.

Modification of support can be obtained based on:

  1. substantially increased or decreased gross income of an obligee or obligor;
  2. substantially increased or decreased needs of an obligee, obligor, or child;
  3. receipt of public assistance;
  4. change in the cost of living for either parent;
  5. extraordinary medical expenses of a child;
  6. a change in the availability of appropriate health care coverage or a substantial increase or decrease in health care coverage costs;
  7. addition of or substantial increase or decrease in child care costs; or
  8. emancipation of a child.

Minn. Stat. § 518A.39, subd. 2, para. (a).

There is a presumption of a substantial change in circumstances, and the terms of an order are rebuttably presumed to be unreasonable and unfair if:

  1. applying the guidelines would change the current order by at least 20 percent and at least $75 higher or lower per month; or if the current order is less than $75 per month, it results in an order at least 20 percent per month higher or lower;
  2. the medical support provisions of the current order are unenforceable;
  3. the health care coverage ordered is not available to the child;
  4. the current order is for a percentage and not a specific dollar amount;
  5. the gross income of an obligee or obligor has decreased by at least 20 percent through no fault or choice of the party; or
  6. a deviation was granted because the child lived in a foreign country and the child no longer resides in the foreign country or the factor is no longer applicable.

Minn. Stat. § 518A.39, subd. 2, para. (b).

A change in the law does not constitute a substantial change in circumstances for modifying a child support order. Minn. Stat. § 518A.39, subd. 2, para. (i).

If the court grants the request for modification, the support order is modified retroactively only from the date the parties were served with notice of the motion for modification. Minn. Stat. § 518A.39, subd. 2, para. (e).

The birth of a subsequent nonjoint child is generally not grounds for a modification of support owed to previous children. However, if a motion to modify support is based on other grounds, the court may consider the birth of the nonjoint child as a factor in determining the support obligation. Minn. Stat. §§ 518A.33; 518A.39, subd.2, para. (c).

If a parent has remarried, the new spouse’s income cannot be considered in calculating the needs or resources of the parent. Minn. Stat. §§ 518A.29, para. (f); 518A.39, subd. 2, para. (d)(1).


If a parent owes both current support and arrears, the support amount can be increased by up to 20 percent per month to cover the arrears. [Note: for forgiveness of arrearages, see “Are there defenses to nonpayment of child support?” on page 16.] Minn. Stat. § 518A.53, subd. 10.

This post is part of a series of posts on Calculating Child Support in Minnesota.

This material and the material in the following posts has been copied from Minnesota’s Child Support Laws, An Overview, drafted by the Minnesota House of Representatives Research Department’s legislative analyst, Lrnn Aves.

This post is part of a series of posts on Calculating Child Support in Minnesota.