Though the Supreme Court handed the gay rights movement a major victory Wednesday by requiring the federal government to recognize same-sex marriages in the 12 states, and District of Columbia, that allow them, the fates of same-sex married couples who move out of those states is much less clear.

In fact, a coalition of gay rights groups is warning same-sex couples who live in the 35 states that ban gay marriage that they may not be able to access a divorce or be eligible for key federal benefits if they get married in a gay marriage state and then travel home.

"Couples who travel to another place to marry and then return to live in a state that does not respect their marriage may be unfairly unable to obtain a divorce, which can lead to serious negative legal and financial consequences," the coalition, which includes the Human Rights Campaign and the National Gay and Lesbian Taskforce, warns in a fact sheet about the decision. "People must make careful decisions when and where to marry, even as we work together to end this injustice."

On Wednesday, the Supreme Court struck down part of the 1996 federal Defense of Marriage Act that defines marriage as only between a man and a woman for the purposes of more than 1,000 federal benefits and responsibilities that deal with marriage. The decision means, in theory, that gay couples in states that allow same-sex marriage should be able to file their taxes jointly, take time off to care for a sick family member without fear of losing their job under the Family and Medical Leave Act, and access other spousal benefits as soon as the decision goes into effect in 25 days.

But the court left untouched a section of DOMA that allows states to refuse to recognize same-sex marriages granted by other states. Currently, 35 states specifically bar same-sex marriage, while New Jersey and New Mexico have no laws either allowing or prohibiting it. (Gov. Chris Christie vetoed legislation legalizing gay marriage last year.)

That means a married couple in New York that moves to North Carolina, for example, will most likely face a legal and bureaucratic maze in trying to figure out what federal benefits they qualify for.

During oral arguments in the DOMA case during the spring, Justice Samuel Alito asked attorney Roberta Kaplan, who was arguing against DOMA, about this hypothetical. Alito asked whether a New York gay couple who moved to North Carolina could qualify for the same federal estate tax breaks that heterosexual married couples get if one spouse dies.

"Our position is only with respect to the nine states ... that recognize these marriages," Kaplan responded. (Since then, three more states have legalized same-sex marriage.)

Even so, it's clear that same-sex married couples will be able to access some federal benefits no matter where they live under the new decision. Some federal agencies, such as those dealing with immigration, use the place where a marriage certificate was issued for their definition of marriage. That means an American citizen married to a same-sex spouse from another country will be able to apply for immigration benefits for him no matter which state he lives in. "Working with our federal partners, including the Department of Justice, we will implement today's decision so that all married couples will be treated equally and fairly in the administration of our immigration laws," Homeland Security Secretary Janet Napolitano said Wednesday.

But other federal agencies, such as the IRS and Social Security, define marriage based on where a couple lives. So a couple's marriage is only valid for the purpose of that agency if it's valid where they live. The Obama administration could order the IRS and other agencies to accept same-sex marriages if they are valid in the state they were issued, but such a move would likely take time.

Because of this discrepancy, the task force of gay rights groups is urging gay couples who live in non-gay marriage states to think carefully before deciding to marry.

"Couples who live in these states should proceed with caution before deciding to marry. Depending on your individual circumstances, getting married may be financially or legally detrimental, especially if you are receiving certain government benefits," the groups say. "Couples should seek out individualized legal advice from a knowledgeable attorney before traveling to another place to marry."

The inconsistency will most likely lead to lawsuits from same-sex couples who could argue Section 2 of DOMA interferes with their constitutional right to travel. (In the past, the Supreme Court has struck down states’ waiting periods for new residents to enroll in welfare programs, holding that they violated the right of interstate travel.) Same-sex couples could also make a broader legal argument that the federal government should define “marriage” based on where a couple got married, not where they currently live.