Normally when spouses divorce, the court names one of them the custodial parent, and the other, the noncustodial parent. In this routine, which prevails in 90 percent of divorces with minor children, the noncustodial parent pays child support to the custodial parent for the benefit of their children. In the case of joint custody, the amount of child support each pays is normally calculated by the court considering the percentage each parent contributes to the couple’s joint income and the percentage of time each parent has physical custody of the children. Unwed parents are obligated to support their children.

If the parent suffers a loss of income, that could be a basis for reducing support; conversely, if the parent’s income increases, that could be a basis for increasing support, according to the ABA. The spouse who wants to make a change over the other’s objection has the burden to show what has changed and why a different amount (higher or lower) should be required. Temporary changes might be result of a medical emergency, a change in employment status or a short-term economic hardship on the part of the receiving parent. A permanent change in child support is often considered when income changes due to a remarriage, when either parent has a job change that affects ability to pay, or when the child involved has new and different needs than were contemplated when the original amount was set.

Changes in the child’s circumstances can be a reason for modifying support. If the child has significant new expenses such as braces or special classes or health expenses that are not covered by insurance that too can be a reason for increasing support.

Significant changes in the income of the parent seeking support also can be a basis for modification. If the custodial parent’s income drops (particularly through no fault of the custodial parent), that might be a basis for increasing support. If the custodial parent’s income increases, that might be basis for reducing support from the noncustodial parent.

A child support payment would not be reduced if a parent quit a full-time job and returned to school. Nor will the child support of a successful brain surgeon who abandons his or her practice to become a street musician. If the payor becomes unemployed and then takes a lower paying job, a reconsideration of the amount of child support due might be appropriate.

When a parent experiences a financial setback, one of the last things that he or she may want to do is incur more expenses by hiring an attorney to try to reduce support. But if the parent has a good reason to reduce support, the money is well spent. If the local court is user-friendly, the parent seeking to change support might try to represent himself or herself.

Once custody has been awarded, courts do not frivolously change the award. Some states apply a special standard for custody modifications sought within the first year or two after a prior custody order for the purpose of discouraging parents from constantly litigating custody and support awards. In those states, the parent must show not only a change of circumstances, but also that the child is endangered by the child’s current environment. After expiration of the one- or two-year period, the courts apply normal standards for modification without having to show endangerment.