Same sex couples are rejoicing after Wednesday's Supreme Court ruling declaring the Defense of Marriage Act unconstitutional. It offers federal recognition of the unions and invites them into a new and potentially lucrative world of shared tax, retirement, estate and employee benefits.
"It will be less costly to be gay," said Debra Neiman, an Arlington, Mass., financial adviser and author of "Money Without Matrimony."
There are two major points of uncertainty that will have to be clarified via new federal and state rules and future court cases.
First, it isn't clear whether couples who were wed in states that sanction same-sex marriage, but reside in states that do not, will be recognized by the federal government.
The second issue involves retroactivity. While gay married couples, widows and widowers can go back and file amended income and estate tax returns, it's not clear whether they can go back longer than three years, the time currently allowed by the Internal Revenue Service for tax returns to be amended.
Here are some other financial implications of the ruling:
Estate taxes: It will mean that spouses can leave each other as much money as they want without paying federal estate taxes, just as married heterosexual couples can. A couple together will also be able to leave as much as $10.5 million, free of estate taxes, to their heirs. Under current law, state-married gay couples don't have those spousal exemptions.
One consequence: Same-sex couples may be able to drop expensive life insurance they were carrying just to pay estate taxes, says John LeBlanc, a financial adviser with Modera Wealth Management in Boston.
New retirement strategies: The hottest retirement strategy among heterosexual married couples involves optimizing Social Security benefits, in which one spouse takes benefits early and then switches to spousal benefits later. That strategy will become available for same-sex couples.
Moreover, same-sex widows and widowers will be eligible for spousal Social Security, so when one spouse dies, the second one can switch to that person's benefits if they are higher.
Big companies may find themselves required to give spousal pension benefits to workers in states that sanction gay marriage but not in states that don't.
Amending tax returns: Moving to a joint federal tax return could cost same-sex couples, since they would no longer be able to optimize their deductions by giving them all to one partner or the other.
Meanwhile, there is the "marriage penalty" -- the tax code is structured with progressive tax brackets, so it can penalize married couples who have roughly equivalent income.
And there is no requirement for married couples to file amended tax returns following this ruling. But some may find that worthwhile -- for a couple with disparate incomes, joint filing may lower their tax burden.
Depending on whether effective dates for the decision are in the future or the past, there may be moves to make as soon as the court acts. Separate filers who will eventually file jointly could make sizable charitable gifts now and apportion them to the partner who will save the most by making them. A retroactive decision beyond January could prompt some to file amended tax returns for previous years.