Although child support in Arizona is calculated based on an income shares approach and the use of guidelines, circumstances often exist that may make a guideline award of child support unreasonable or unfair. There is also a rebuttable presumption that a parent can be gainfully employed on a full-time basis, at least at the minimum wage level. If a parent is unemployed, potential income may be imputed unless that parent can show that he/she is not voluntarily unemployed or underemployed. In determining potential income, situations where one parent is self-employed or has been a stay-at-home parent require a more nuanced approach.
Then there is the issue of modification of a previously established child support order. Whether a parent's increase or decrease in income warrants a modification depends on whether the parent requesting the modification can demonstrate that there has been a substantial change in circumstances. There are also situations where a parent's time with his/her child will increase or decrease. Any time there is a modification in the parents' parenting time arrangement, child support needs to be reconsidered.