The past decade has seen tremendous progress in the battle for marriage equality. State bans onsame sex marriage are falling one after another, granting these families the legal recognition they were denied for too long.On June 1, 2011, the Civil Union Act became effective and Illinois not only began granting civil unions, but also giving immediate recognition to “substantially similar legal relationship[s] . . . legally entered into in another jurisdiction.” 750 ILCS 75/60. Three years later, on June 1, 2014 same sex marriages were fully recognized in Illinois under the Religious Freedom and Marriage Fairness Act which incorporated the same reciprocity language for marriages previously entered in other states.The reciprocity language of the Civil Union and Marriage Fairness Acts is intriguing because many couples did not wait until Illinois recognized civil unions or same sex marriage to get married. Instead, they went to other states as early as 2002 to get their civil unions or 2004 for their marriages.When the Illinois legislature gave recognition to out-of-state marriages and civil unions in June 2011, it did not state whether Illinois would recognize the marital property rights attendant to those marriages retroactive to the date of the parties’ marriage, or upon the effective date of the Act. Therefore, the new law created confusion since it was entirely unclear what would happen to the support or marital property rights of a couple who married in another state before 2011, lived in Illinois throughout their marriage, and now wanted to divorce in Illinois.Consider a hypothetical couple who lived and worked in Illinois all their lives and wanted to get married in 2004. Since Illinois did not recognize same sex marriages, the couple flew to Massachusetts for a weekend, got married then returned home to Illinois. Since Illinois did not recognize their marriage, the couple had no protections or responsibilities under Illinois family law. The Illinois Marriage and Dissolution of Marriage Act (“IMDMA”), the statute which sets forth guidelines for paying support and dividing property, did not apply to them. Moreover, because Illinois did not recognize their marriage in the first place, they could not get divorced.So the following questions remain unanswered:When did marital property start to accrue for this couple?Was it in 2004 when the parties were married in Massachusetts?Or was it 2011 when Illinois recognized their marriage?At first blush, 2004 may seem the most logical and equitable answer. If so, however, what rights and responsibilities did the parties have between 2004 and 2011 when their marriage had no legal recognition in Illinois? The couple had no reason to protect their assets or income from spousal property and support claims during that period because Illinois did not grant them any spousal property or support rights to protect. Since their marriage was not recognized in Illinois, the couple could not have stopped the accrual of marital property during this time period. And even if the couple had wanted to protect themselves by getting a divorce, they had to legal recourse available to do so since they were not legally married under Illinois law.From a pure statutory interpretation perspective, the issue seems simple. InDoe v. Diocese of Dallas, the Illinois Supreme Court ruled that statutory amendments creating new substantive rights may not be applied retroactively unless they are written as explicitly retroactive in application. Marital property rights are substantive rights. Neither the Civil Union Act nor the Marriage Fairness Act expressly provides whether they are to be applied prospectively or retroactively. Accordingly, in the absence of an express provision, the Acts must be applied prospectively only. Accordingly, the answer should be that marital property rights for same sex couples did not start to accrue in Illinois until June 1, 2011 regardless of a prior marriage date.Regardless of how simple the statutory interpretation should be, this author has litigated this issue at the trial and appellate levels and has met stiff resistance from the bench to the position that marital property rights for same sex couples should not accrue until after June 1, 2011. From this author’s perspective, it appears that the courts are interpreting this argument as an anti-marriage equality position that same sex marriages are somehow less than equal because they would have a standard statutorily mandated start date for the accumulation of marital property when heterosexual marriages do not.But that assumption could not be further from the truth. This is an issue of equal protection under the law between divorcing spouses. No law should retroactively impose substantive responsibilities (here the obligation to share income or assets) on citizens. If a marriage was not recognized in Illinois until June 2011, we cannot now go back and pretend that the state always recognized it. While retroactively granting spousalrightsmay feel like the right thing to do, retroactivelyimposing responsibilitieson our citizens which they did not have at the time in question is patently unfair and inequitable to those citizens – especially for the spouse who amassed the greater separate estate during that pre-June 2011 era.So what can we learn from this conundrum at this time? To this author’s knowledge, no decisions have yet been reached and the issue in Illinois is still undetermined. Going forward, same sex couples who seek a divorce in Illinois should know that there is no clear answer as to when they started to accrue their marital estate. Until the Illinois Legislature amends the Marriage Fairness Act or the Illinois Supreme Court clarifies the existing law to specify whether or not the law should be applied retroactively, there is a significant variance in possible outcomes. Given the current uncertainty on this issue, couples in this situation may find a mediated out of court settlement far more appealing.