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Valentine's Day is for love, couples and proposals. Now that voters in three more states (Maine, Maryland and Washington) have legalized same-sex unions, more gay partners likely will be popping the question on Feb. 14.

David Rae and Ryne Meadors of Los Angeles have their rings picked out and are planning a summer 2014 wedding. But even if the state of California would grant the same-sex couple a license to get married, they wouldn't get one -- at least not now.

"People are assuming that if they get married they'll have all these benefits because … the opposite-sex couples they know have them," said Rae, a certified financial planner and vice president of investments for Trilogy Financial Services in Los Angeles. "But the majority of the benefits are on the federal level."

Joshua Hatfield Charles, who helps represent the Certified Financial Planner Board of Standards, disagrees. He married his partner, Dixon Charles, in Connecticut four years ago, and the pair plan to remarry on Feb. 16, now that their home state of Maryland is issuing same-sex marriage licenses.

"The protections are fabulous," said Charles, adding that marriage offers significant legal and contractual benefits. "Relationship recognition -- that's huge."

But marrying can pose financial disadvantages for same-sex couples. That's largely because the federal government doesn't recognize such marriages, even though eight states (Connecticut, Iowa, Maine, Maryland, Massachusetts, New Hampshire, New York, Vermont and Washington) and Washington, D.C., issue marriage licenses to same-sex couples, and several others acknowledge civil unions or domestic partnerships.

Liz Weston

Should that keep you from saying "I do"? Not necessarily, but you should know what you're getting into.

At a minimum, you'll be filing multiple tax returns: as single filers for federal returns, and marrieds filing jointly at the state level. State tax returns often depend on federal figures, so a "dummy" federal return has to be created (although it won't be filed). All that work can double your tax preparation costs, Rae said.

You may owe more taxes as well, particularly if you're both big earners. On the state level, you could push yourselves into a higher tax bracket or wind up losing deductions that phase out at higher incomes. At a minimum, you should talk to a tax professional before you make a decision.

Two big benefits of legal marriage involve hospital visitation and estate planning. Spouses married in states that issue licenses to same-sex couples have automatic inheritance and visitation rights. Otherwise, same-sex couples have to craft legal agreements, which could be upended by other relatives if courts deem those relatives to have superior legal standing, Charles said.

According to Stuart Armstrong of Centinel Financial Group in Needham Heights, Mass., "Visitation rules while hospitalized and the right to make medical and financial decisions would be strengthened in states where marriage is recognized, particularly in the absence of documents indicating those designations." Couples still need to be careful when traveling to states that don't recognize gay marriage, so creating powers of attorney and medical care directives can be a wise backup.

Additionally, several states where gay marriage is legal levy estate and/or inheritance taxes on assets bequeathed to heirs but allow unlimited amounts to pass to spouses tax-free. Since Maryland, for example, levies taxes on estates worth more than $1 million, plus an inheritance tax of 10%, marriage there has significant potential tax benefits, Charles said.

However, the "unlimited spousal exemption" that protects married people from estate taxes doesn't extend to same-sex marrieds on the federal level.

"I can call him my spouse, but the IRS doesn't care," Rae said.

That's just one of the 1,138 rights, obligations, protections and privileges of marriage identified by the Government Accountability Office in 2004 that don't apply to same-sex couples.

Unlike opposite-sex married couples, gay marrieds also can't:

  • claim Social Security benefits based on a spouse's working record.
  • fund an IRA or Roth IRA for a nonworking spouse.
  • split a retirement fund or other assets without potential tax bills if they divorce.
  • exempt health care benefits for a spouse from their federal income.

Planner Sheryl Garrett recounts the story of a couple who were delighted when one partner's company added health care insurance for domestic partners. The other half of the couple was self-employed, so getting reasonably priced health insurance was tough.

"They were thrilled right up until they got the W-2," said Garrett, a CFP who authored a book on same-sex finances. The tax form showed the partner's health insurance was a taxable benefit, she said. "They had a little over $3,000 in additional tax liability."

These differences could melt away if the U.S. Supreme Court affirms a fundamental right to same-sex marriage. The court is currently considering two cases that argue the issue, including one that challenges the Defense of Marriage Act, the 1996 federal law that defines marriage as a legal union between one man and one woman.

"Personally, I don't think there's enough benefit until (same-sex marriage) is federally recognized," said Garrett, who lives in Kansas with her partner and their daughter. "But I'm really happy that people are going forward and taking advantage of their right where they can. Without that, a lot of people may not recognize this is something folks want."

The financial planners all encourage same-sex couples to consult with certified financial planners who are familiar with these issues. (There's even a certification for Accredited Domestic Partnership Advisor, or ADPA.) The planners also recognize that some will want to marry regardless of any potential downsides.

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"To a lot of people, it's a huge thing," Garrett said. "It's not just a financial thing."

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Liz Weston is the Web's most-read personal-finance writer. She is the author of several books, most recently "The 10 Commandments of Money: Survive and Thrive in the New Economy" (find it on Bing). Weston's award-winning columns appear every Monday and Thursday, exclusively on MSN Money. Join the conversation and send in your financial questions on Liz Weston's Facebook fan page.

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