There are a lot of steps to check off your to-do list before you claim Social Security benefits for the first time. The decision you make about when to file for these benefits can affect the monthly and lifetime income you end up with.

If you're married, then here's one of the most important moves of all to make before you claim your Social Security checks.

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Be sure to do this before you start Social Security benefits

If you are married and thinking about claiming your Social Security benefits, one of the first and most important things you should do is to coordinate a filing strategy with your spouse.

See, there are a lot of different choices that married couples may need to make in order to maximize the combined lifetime income from Social Security that comes into the household. That's because of the possibility that one spouse could receive spousal benefits and/or survivor benefits instead of their own retirement checks. 

Spousal benefits could equal up to 50% of your husband or wife's primary benefit amount, depending when you claim them. If you aren't eligible for Social Security on your own because you didn't work enough or if you earned much less than your spouse did and your benefit amount is pretty low, spousal benefits could provide you with more money than your own retirement benefits would. But you can only claim spousal benefits once your husband or wife has started getting their own checks.

Survivor benefits, on the other hand, could be a lifeline after your husband or wife passes away. When one spouse dies, the other gets to keep the higher of the two checks coming into the household. If the higher earner maximized their Social Security benefits with a smart claiming strategy, this could mean a lower-earning spouse who was widowed gets hundreds or even thousands of dollars more money to live on. 

Since spousal and survivor benefits can make a big impact on lifetime Social Security payments (and on your financial security as a couple in retirement), you'll want to think about who should claim what types of benefits -- and when. This way, you can come up with a smart approach that takes all of your potential sources of Social Security payments into account both now and in the future.

For example, the lower-earning spouse might want to claim their own retirement benefits ASAP to enable the higher earner to delay their claim as long as possible and max out survivor benefits. Or, by contrast, the higher earner may want to start their checks ASAP to open up the door to spousal benefits that would otherwise not be available. These are decisions that you'll need to talk through with your partner -- and perhaps a financial advisor -- before rushing to claim Social Security.

The reality is, once you start your Social Security payments, it's difficult to undo the claim -- and you may not realize you could be dooming your widow to a life of financial struggle or giving up the chance to maximize combined lifetime benefits. You don't want to rush into this decision without understanding all of the options, so take the time you need to coordinate together and make a plan that's right for you both.