Dear Liz: My registered domestic partner and I are both 64. We have similar incomes, similar 401(k) accounts and own a home together. We plan on retiring at 66, at which time we will also get similar Social Security benefits. We are each other’s beneficiary on all insurance, accounts, etc. My question: Now that the Supreme Court has made it legal, would it benefit us financially to get married? We’ve never felt an emotional need for that validation but are questioning whether it would make sense for other practical reasons.

Answer: When incomes are dissimilar, there’s a strong argument to be made for marriage. The lower earner may get more from a Social Security spousal benefit than from his or her own retirement benefit. In addition, the lower earner could get a much bigger survivor benefit, since a survivor gets the larger of the couple’s two Social Security checks.

If either of you had a traditional pension, a spouse would be entitled to survivor benefits that an unmarried partner can’t claim. And if you were of dramatically different ages, marriage would allow a younger survivor to put off starting mandatory withdrawals from inherited accounts.

Marriage also has estate planning advantages, but those primarily benefit wealthy couples (see above). If you do remain unmarried, you’ll want to make sure you both have powers of attorney for healthcare and finances so you can make decisions if the other becomes incapacitated.

There are many other benefits to marriage, which the self-help legal publisher Nolo has summarized at http://bit.ly/1mOmpZA. You also might want to talk to a fee-only financial planner who has experience with same-sex couples to make sure that your assets and rights are adequately protected if you remain unmarried.