In a case of first impression, the Illinois Appellate Court has now decided where a child support modification case must proceed when the parents live in different states.The increasing mobility of our society often creates jurisdictional contests when one or both parents relocate after a divorce and one of them initiates litigation over child support. Where should a child support recipient file a petition for modification of support when the parents live in different states? Consider the following example: A couple marries in State A and later moves to State B. While residing in State B, they have a child. Some time later, the couple decides to dissolve their marriage in State B. Thereafter, the child support recipient under State B’s judgment for dissolution of marriage moves back to State A with the child and wishes to seek an increase in child support. The child support payor remains in State B. Where is the proper forum for the parent to seek a modification, State A or State B? In a case of first impression, the Illinois Appellate inIn re the Marriage of Vailas,2010 WL 4643634 (Ill. App. 1 Dist, Nov. 16, 2010), clarified the analysis that must take place underthe Uniform Interstate Family Support Act(UIFSA) to answer that very question.At issue in theVailascase was whether the trial court in Illinois (State A, in the example above) had jurisdiction to modify a child support order originally entered by Texas (State B, in the example above) when the payor father remained a resident of Texas. The trial court ruled that Illinois obtained both subject matter and personal jurisdiction because the mother personally served the father with her Petition for an Increase in Support while he visited with his son in Illinois. However, the Appellate Court reversed the trial court’s ruling and held that personal service alone does not vest the court with jurisdiction to modify the Texas order.For the first time in Illinois, the Court interpreted Sections 201 and 611 of the Uniform Interstate Family Support Act (UIFSA) and their application in a child support modification proceeding. Drafted by the National Conference on Uniform State Laws, UIFSA was the solution of the jurisdictional and competing order contests that arise in multi-state family support enforcement and modification litigation. In 1996, Congress mandated adoption of the statute by all states that wanted to receive federal funding for child support programs, and by 1998, every state had enacted it. The purpose of the statute was to give the state courts uniform rules to follow so as to prevent multiple, often competing child support orders entered by different states.UIFSA covers a variety of support obligations, including both child and spousal support. TheVailascase was strictly a child support modification proceeding, as opposed to a support enforcement proceeding which, has its own set of rules and guidelines. InVailas, the mother sought an increase – a modification – of the existing Texas child support order in an Illinois court. The Appellate Court ruled that in order for Illinois to hear the matter, it must have both personal jurisdiction over the father and subject matter jurisdiction over the issue in controversy. Pursuant to Section 201(b) of UIFSA, a court can not have personal jurisdiction unless it also has subject matter jurisdiction, and it was the latter issue that became the pivotal point in the case.In child support modification (not enforcement) proceedings, subject matter jurisdiction is obtained only if one of two sets of conditions is first met. The first is that:1. Neither the child, nor the petitioner who is an individual, nor the respondent resides in the issuing state;2. A petitioner who is a nonresident of this state seeks modification; and3. The Respondent is subject to the personal jurisdiction of the tribunal of this State.Alternatively, the order may be modified if Illinois is the state of residence of the child, or a party who is an individual is subject to the personal jurisdiction of the tribunal of this State and all of the parties who are individuals have filed consents in a record in the issuing tribunal for a tribunal of this State to modify the support order and assume continuing, exclusive jurisdiction. In other words, the parties may agree to allow a state where one of them resides to maintain jurisdiction over the matter. InVailas, Illinois did not gain subject matter jurisdiction over the case because the father remained a resident of Texas (the issuing state) and the petitioner (the mother) was not a non-resident of Illinois.In crafting its opinion, the Appellate Court noted that the traditional notions of personal jurisdiction do not apply to post-judgment support modification cases in order to avoid “jurisdiction by ambush,” which could happen when a parent seeking to exercise visitation rights, or engaging in unrelated business activity in a state could be involuntarily subjected to protracted litigation in an inconvenient forum in a modification proceeding merely because he or she was served with a modification petition while present in that state. However, the analysis does not end with subject matter jurisdiction. If the requirements are met under Section 611, personal jurisdiction must also be obtained under Section 201.In the end, if any party remains a resident of the issuing state, that state will retain continuing, exclusive jurisdiction to modify its original order. However, if all of the parties have left the issuing state, the state that has continuing, exclusive jurisdiction is the state in which the respondent resides. Of course, the parties can agree that a state in which the child resides or that has personal jurisdiction over a party may assume jurisdiction, and by filing the proper papers in the issuing state, the matter can be permanently moved to another state.