In addition to the modification standard discussed on the Modification page (add link), there is an additional way to change child support that does not apply to visitation or primary custody. After three years from either the last order date or date of the agreement, the court can "review" the child support amount to make sure it is in compliance with the Texas child support guidelines. This means that the court will calculate the paying parent's guideline child support based on his/her current income and circumstances and determine whether the new amount differs (either higher or lower) by 20% or $100 per month and order the new amount. Usually this sort of review is due to a significant change in the paying parent's employment status. It can be requested by the receiving parent (to raise child support) or the paying parent (to lower child support).

This review would only take place after three years, but the other kind of modification for child support can be brought at any time as long as the parent requesting the modification can prove a material and substantial change of circumstances for one or both of the parties or the child and that the change is in the child's best interest.