Modifying Support and Custody Arrangements

Request a Case Evaluation

  • Hidden
  • This field is for validation purposes and should be left unchanged.

Modifying Support and Custody Arrangements

As part of the divorce process, courts will evaluate whether child or spousal support is appropriate, and what child custody arrangements are in the child’s best interests. Some form of joint custody arrangement is increasingly common. Circumstances can change, from remarriage to new job opportunities to moving to care for a sick relative. With these changes, it may be necessary to change the requirements of the divorce decree.


Missouri law states that a custody agreement will not be modified unless “a change has occurred in the circumstances of the child or his custodian and that the modification is necessary to serve the best interests of the child.” There is a distinction between modifying physical custody and modifying visitation. Modifying physical custody requires a “substantial” change in circumstances, whereas modifying visitation will be done whenever it is in the best interests of the child. This is an important distinction, as it means that changing which days one parent has visitation with the child has less stringent requirements than changing which parent has actual physical custody.

Child and spousal support

To modify the amount of child support paid by one parent, the parent must show that circumstances have changed so much that the existing arrangement has become unreasonable.

In the case of child support, the spouse paying support makes a prima facie showing (that is, a presumption that must be rebutted) of a substantial change when his or her income changes by 20 percent or more. This does not mean that it is impossible to show a change in circumstances if the change is less than 20 percent, merely that the 20 percent change is considered likely to be significant.

With spousal support, the base test is the same, namely that circumstances have changed so much that the existing arrangement has become unreasonable. The court will also look at the respective finances of the spouses and the “reasonable needs” of the spouse who is receiving support minus expenses attributable to the children. In one case from 2010, Ferry v. Ferry, the Missouri Supreme Court found that a wife (the custodial parent) could not use the full $6,138 per month in expenses that she claimed, because $2,070 was directly attributable to the children. This number is significant because it is the amount that the court used to determine how much the husband was responsible for paying in support, and so may be grounds for modification of that amount.

A change of circumstances can take many forms, and must be acted upon in the proper way. In the event of a change in circumstances, or where the other parent or former spouse has asked the court to change support or custody, you should contact a lawyer immediately to ensure that your rights are protected.