If you think prenups are controversial, brace yourself. Postnups are on the rise.
Postnuptial agreements—similar to prenups, but for married couples—are gaining acceptance, with nearly all 50 states now allowing them. The agreements can cover everything from how to divide financial assets in divorce to limits on partners' weight gain, just as prenups can. And in a survey of divorce lawyers by the American Academy of Matrimonial Lawyers, 51 percent saw an increase in postnups and 46 percent saw no change from 2009 to 2012.
Now that the Supreme Court has struck down the Defense of Marriage Act, or DOMA, experts say more postnups could be in the offing.
It's not because newly married same-sex couples' unions are likely to suddenly founder. On the contrary: They will need to reallocate some of their property now that they can tie the knot, according to Marilyn Chinitz, a partner at Blank Rome.
"You can anticipate that couples are going to want to address property rights in a postnup for property that otherwise would have been deemed separate, because they acquired it before the marriage," she said. "Many couples will want to give recognition to those assets and put them in the marital estate."
Chinitz said DOMA's demise could lead to a moderate pickup in postnups. But Randall Kessler, a partner at Kessler & Solomiany and past chair of the American Bar Association's family law section, expects a surge in both prenups and postnups.
"Now that federal and related benefits cannot be denied to a same-sex spouse based on DOMA, those who have the benefits may want to protect them," he said. And couples who have rushed to marry in the wake of the ruling "may not have wanted to delay the wedding to have to negotiate a prenup. But they can still get a postnup."
(Read More: Being Financially Prepared for DOMA Ruling)