Social Security is an important source of income for retirees, but the rules surrounding it are complicated. This is especially true if you're married, as there are all sorts of special regulations that could affect the ideal time for you and your spouse to start getting your checks. 

If you're legally wed, there are three rules you absolutely need to know to make the best, most informed choices in order to maximize benefits. Here's what they are. 

Two older adults taking selfie together.

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1. You can't claim spousal benefits until your spouse starts getting their own checks

Spousal benefits can be a valuable source of Social Security income for those who didn't work much on their own, or whose earnings weren't as high as their spouses.

If you're interested in claiming spousal benefits, they could be worth up to 50% of the amount your spouse is entitled to at full retirement age, or FRA (although you'll get less if you start your spousal benefits before your own FRA). 

The catch, however, is that if you're claiming benefits on your spouse's work record, you can't do that until your husband or wife claims their own benefits first. So, if, for example, you're hoping to claim spousal benefits on your husband's work history but he wants to wait until 70 to get his own checks, you'll need to delay a long time.

You can claim your own retirement benefits in the meantime, though, if you're eligible. This is often a good strategy because the lower-earning spouse could start getting Social Security retirement checks early to bring some retirement income into the household, then switch to spousal benefits after their higher-earning partner files. 

2. Claiming Social Security early shrinks survivor benefits for your spouse

When one spouse dies, the surviving widow(er) can claim survivor benefits. It makes sense for a surviving spouse to claim them if the person who died was the higher earner and thus had a higher retirement benefit than the widow's own benefits are worth. 

Survivor benefits can equal up to 100% of the amount the deceased would have been entitled to at full retirement age if your spouse passes away before FRA. They'll shrink if you claim them early, though. 

However, if your deceased spouse claimed benefits ahead of his own FRA, thus reducing the amount, the survivor benefits you get will be lower. If, on the other hand, your deceased spouse had waited to claim benefits beyond FRA and thus increased their monthly checks, you'd get to keep this higher benefit for life after he passed. 

If you're the higher earner and want to make sure your spouse gets the most money possible if you pass on, wait to start your Social Security for as long as you can until age 70. And if you're the one claiming survivor benefits on your deceased spouse's work record, you may also want to delay starting until your own full retirement age. 

3. Spousal and survivor benefits aren't eligible for delayed retirement credits

Delaying a claim for Social Security beyond full retirement age increases your retirement benefits due to delayed retirement credits that can be earned until 70. That's why waiting is often a smart move (especially if you'll leave behind a partner who may rely on survivor benefits). 

But, delayed retirement credits don't apply to spousal or survivor benefits. In other words, if you're claiming either, there's no advantage associated with waiting beyond your own FRA to start your payments. If you do, you'll just be leaving money on the table and won't see a corresponding increase in your monthly check amount.

These rules can be confusing, but knowing them is important so you can make the right choices that allow you to maximize Social Security income for both you and your spouse.