MARRIAGE AFFECTS FINANCES,

If same-sex couples wed, they gain access to legal and financial benefits. But they — and anyone else thinking about marrying — also bear some often-overlooked costs.

“You’re telling the government: I will take care of this person legally and financially if something happens to them,” said Debra Neiman, a financial planner in Arlington, Massachusetts.

So, ignoring the whole happiness thing, here are some of the practical pros and cons of marriage.

PRO: RETIREMENT

Married people can share each other’s retirement funds and Social Security benefits. If one dies, the remaining spouse can inherit pension payments or Social Security survivor benefits. When you’re married, it’s far easier to roll over a spouse’s individual retirement accounts or 401(k)s after he or she dies.

Marriage lets you use some complicated techniques to boost Social Security payments — for example, by accessing one spouse’s benefit early but not tapping the other until he or she is eligible for the maximum payout at age 70.

PRO AND CON: TAXES

Taxes are complicated, but here’s one rule of thumb: Getting married tends to lower a couple’s income tax burden if one spouse earns a lot more than the other. If a lawyer and a stay-at-home dad marry, for example, they’ll almost certainly save money on taxes. Couples can face a higher tax bill, however, if both spouses earn about the same.

The marriage penalty can be especially high — in some cases, tens of thousands of dollars a year — if both are well-paid professionals with sixfigure salaries. If you and your partner each make $300,000 a year, you’re paying a top tax rate of 33 percent. If you get married, your $600,000 will be taxed at 39.6 percent.

When couples are married, they can seamlessly share money, property and possessions between them. If one dies, the other can inherit everything and pay no taxes. For unmarried couples, it’s not so easy.

If you give more than $14,000 to your partner in one year, you may need to file a gift tax return. If you die with an estate of more than $5.4 million and leave it to an unmarried partner, a federal estate tax can be levied, with a top rate of 40 percent.

CON: GOV’T BENEFITS

Because getting married can boost your household income, it may make you ineligible for certain kinds of help — financial aid for college, for example, or programs designed to make it easier to pay back student debt. The U.S. Income-Based Repayment program, or IBR, limits your student loan payments to a percentage of your income. A single person making $40,000 a year, with $100,000 in student debt, might pay $280 a month. If that person marries someone earning $40,000 a year, his or her payment could jump above $700 a month. If the spouse makes much more than that, they may become ineligible for IBR altogether.

Medicaid, the government health insurance program, can pay for

long-term care expenses, but only if seniors are poor enough. It can make sense for a couple to stay single so that an ailing partner can qualify for Medicaid.

Pro: ProPerty

When they own property together, unmarried couples must worry about things that married folk take for granted. If one partner dies without the right will, or without life insurance to pay estate taxes, the other can easily lose the home. Also, one member of an unmarried couple may be helping pay the mortgage, but unless named on the title of a home, will have trouble claiming a mortgage interest tax deduction on taxes.

Mostly Pro: FAMily

A legal marriage can sort out a variety of issues faced by parents. For example, a parent often has had to legally adopt a child born to her partner. That may not be necessary anymore.

There is one exception. Same-sex couples thinking about adopting overseas may want to stay unmarried for the time being. In countries where Americans adopt, officials often discriminate against gay couples and may be more open to a single person.

Pro: iMMigrAtion

If they’re legally married, U.S. citizens and permanent residents can get their spouses green cards that allow them to live and work in the U.S.

Pro AnD Con: DivorCe

Divorce can be expensive, and afterward a person can lose prized possessions to an ex or be stuck paying alimony for years. Then again, the process can be a lot fairer than none at all, especially if there’s a lot of property to split up. The rules can protect the financially weaker person.

Pro: heAlth CAre

Workers can usually cover spouses through employers’ health insurance. Married people can also cover their spouses’ health expenses through flexible spending accounts and health savings accounts.

Married couples automatically get the right to visit a spouse in the hospital and make medical decisions on his or her behalf. If your spouse is sick, you have the right to take time off from work through the Family and Medical Leave Act.

Con: Fights

When you get married, you can be on the hook for your spouse’s debts and bad credit history. Love can keep you together. Money can tear you apart.