Here's When Remarrying Can Cost You Social Security Benefits

Many retirees rely heavily on Social Security: The Social Security Administration reports that more than half of married couples and almost three-quarters of single retirees get at least half of their income from the program in retirement.

For those who've been married previously, Social Security commonly pays two types of benefits: spousal benefits (for divorced spouses who qualify) and survivors benefits (for those whose spouses have passed away). But of course, being divorced or widowed doesn't mean you're destined to stay alone. New love may surprise you. But if that relationship grows, it could lead to a much less pleasant surprise: discontinued Social Security benefits.

What Divorced Spouses Must Consider

Social Security recognizes the potential financial damage a divorce can do, and so it provides many divorced spouses with the same benefits they'd be entitled to receive if they remained married. Specifically, if you were married for at least 10 years, then you can claim spousal benefits based on your ex-spouse's work history.

Even if your ex-spouse remarries, you don't lose your Social Security benefits. That also doesn't reduce anyone's benefits; both you and your ex's new spouse both can claim spousal benefits if the necessary conditions are met.

But once you remarry, you become entitled to take spousal benefits based on your new spouse's work history after a short waiting period. But you lose the ability to claim benefits based on your ex-spouse's work record. If your ex had a higher income than your new spouse, then you could see your benefit shrink as a result.

For Surviving Spouses, Social Security Is More Complicated

If your spouse dies, then you'll be entitled to receive survivors benefits. Those benefits typically equal your spouse's retirement benefit, which is usually substantially higher than spousal benefits.

Like those who've divorced and whose ex-spouse is still living, widows and widowers face some potential pitfalls if they remarry. But with surviving spouses, Social Security's rules are more complex and seem almost arbitrary.

For most surviving spouses, if you haven't yet reached age 60 and get remarried, then you won't be entitled to survivors benefits based on your deceased former spouse's work history. Instead, you'll have to claim spousal benefits from your new spouse and potentially get survivors benefits on your new spouse's work history in the future.

Rules Change for Older People

But if you're 60 or older, Social Security treats you differently. Even if you remarry, you're still entitled to survivors benefits on your deceased former spouse's work record. Again, you're not allowed to double-dip, as you'll only be entitled to additional benefits if they exceed what you're getting as a surviving spouse. Nevertheless, the rationale for putting people younger than 60 in jeopardy of losing benefits while those 60 or older face no such worries isn't entirely clear.

As if that weren't enough, you can sometimes get back benefits even if you initially lost them. If a second marriage also ends in death or divorce, then you may be able to claim benefits based on your first spouse's work history.

Understanding the intricacies of Social Security as a spouse can be tough. But given the potential for problems if you don't consider the financial implications of marital decisions, it's important to get a handle on the rules so you can make an informed choice.

You can follow Motley Fool contributorDan Caplingeron Twitter@DanCaplingeror onGoogle+. Motley Fool retirement experts offer a free report on a simple strategy to use a little-known IRS rule to boost your retirement income.