Chances are, Social Security will end up being a key income source for you in retirement, so the last thing you want to do is file for benefits at the wrong age. Though those benefits are based on your 35 highest-paid years on the job, the age at which you claim them will influence the amount you collect each month as a senior. These crucial moves can help you avoid filing for Social Security at a bad time.

1. Know your full retirement age

If you file for Social Security at your full retirement age, you'll get the exact monthly benefit your earnings record entitles you to. Here's what that age looks like, depending on when you were born:

Year of Birth

Full Retirement Age

1943-1954

66

1955

66 and 2 months

1956

66 and 4 months

1957

66 and 6 months

1958

66 and 8 months

1959

66 and 10 months

1960

67

Data source: Social Security Administration.

In a recent study, 76% of older workers didn't know their full retirement age. And that's a problem, because if you file early, you'll reduce your benefits in the process. The Social Security Administration will allow you to start collecting benefits at 62, but you'll slash your monthly payments for each month you file ahead of full retirement age.

Older man in dress shirt and tie holding a pair of eyeglasses and putting his finger to his mouth as if deep in thought

Image source: Getty Images.

You should also know that if you delay benefits past full retirement age, you'll boost them by 8% a year up until you turn 70. Therefore, commit your full retirement age to memory and plan around it.

2. Assess your health

Social Security is technically designed to pay you the same lifetime total regardless of when you initially file. The logic is that while your benefits might get reduced on a monthly basis if you file before full retirement age, you'll collect more individual payments in that scenario. On the flip side, if you delay benefits past full retirement age, you'll increase them in the process, but you'll get benefits for fewer months.

This formula, however, assumes that you'll live an average life span. If you pass away at a younger age than the typical senior, you'll generally lose out on lifetime income by waiting to file. On the other hand, if you live a longer life, you'll usually gain financially by delaying benefits for as long as you can.

Let's imagine you're entitled to $1,500 a month if you file at your full retirement age of 67. Claiming benefits at 62 will reduce each monthly payment you get to $1,050, but you'll effectively break even under both scenarios around age 78 1/2. But if you die at 75, you'll come out almost $20,000 ahead by filing at 62 rather than 67.

That's why you should evaluate your health before filing for benefits. If you're in good shape and therefore think you might live a long life, you might choose to wait on Social Security. But if you don't think you'll live very long, it might pay to claim benefits as early as you can.

3. Sync up with your spouse

If you're single, you'll only have to take your own needs into account when filing for Social Security. But if you're married, you'll also need to think about what's good for your spouse. For example, if your spouse never worked and is planning to collect Social Security spousal benefits based on your work record, he or she can't collect until you file. As such, you might adjust your filing age to give your spouse access to benefits sooner.

Also keep in mind that your spouse is entitled to survivor benefits if you pass away first. If your spouse is likely to outlive you by many years, delaying benefits and growing them could provide the survivor with a more substantial income stream for life, even if you get less money in your own lifetime than you would by filing earlier.

The point? Work with your spouse to devise a filing strategy that suits both of you.

The age at which you claim Social Security affects your finances for the rest of your life. Weigh your choices carefully so you don't wind up regretting your decision down the line.