In WA, a support recepient can ask for a modification of child support once every two years just because of the passage of time, or can ask for a modification sooner if there is a change in the circumstances of either party that would justify it. A cost of living increase hardly seems worth the trouble, though.
There is an advantage to including language in your support order requiring both of you to exchange tax returns every year on May 1. That way, each can determine if there is a basis for a change or not. Please don't hesitate to find a local attorney who can help you analyse this in person, looking at the documentation. Elizabeth Powell
An adjustment is different than a modification. The child support order may allow an adjustment after less than two years, but can't make parties wait for an adjustment more than two years. Adjustments are generally appropriate to change the transfer payment, but no other part of the support order.
A modification requires a showing of a substantial change in circumstance. See RCW 26.09.100 and RCW 26.09.170. There are a variety of exceptions to the time periods for modifications and adjustments.
A change in income alone, if large enough, may be adequate basis for a modification of child support, not just an adjustment. In re Marriage of Scanlon, 109 Wn. App. 167, 173-74, 34 P.3d 877 (2001).
The answer depends on the jurisdiction and the terms of either your settlement agreement or the final judgment of dissolution. In brief, there needs to be a change in circumstances that was substantial enough to justify a court re-opening a closed divorce file. There is not a particular amount of time that needs to pass, but rather a particular magnitude of change in either your circumstances or those of your former spouse needs to occur.
In Illinois there is no maximum in terms of the amount of times a party can seek increases in support. However, the person seeking modification must have *new* evidence to justify the modification if he or she sought a modification in the past. (That is, a payee can't try to seek a modification twice on the same evidence). The law governing this is 750 ILCS 5/510. Child support is always reviewable by the court, and cannot be made non-modifiable. The support recipient generally must show that there exists a "substantial change in circumstances" to justify the change in support. In Illinois, a COLA increase is the same as a raise, Illinois considers income from all sources as income for child support purposes. If the increase is minor, the court might not allow an increase in support. Illinois courts have held that an increase in the payor's income does not necessarily correlate to a direct equal increase in child support. Usually the payee has to show both an increase in income as well as increased need on the part of the minor children, but this is not an absolute requirement. Many people are able to obtain increased support simply based on the increased income of the support payor, but the increase has to be substantial (rule of thumb I've always heard was 10%).