Millions of seniors use Social Security to pay their living expenses, handle unplanned bills, and enjoy retirement to the fullest. And while those benefits were never designed to sustain retirees in the absence of other income, the reality is that a large chunk of seniors depend on them quite heavily. In fact, an estimated 21% of older married couples and 44% of unmarried seniors look to Social Security to provide 90% or more of their income.

Given the important role Social Security might play in your future, it pays to do what you can to prevent your benefits from getting needlessly slashed. Here are a few ways to go about that.

Pile of Social Security cards.

IMAGE SOURCE: GETTY IMAGES.

1. Know your full retirement age

Though your Social Security benefits will be calculated based on your earnings record (specifically, your 35 highest years of earnings), the age at which you file for them will impact the amount you collect each month. If you file at full retirement age, or FRA, you'll get the exact amount each month that your earnings history entitles you to, but if you file before FRA (which you're allowed to do), you'll slash your benefits in the process.

Your FRA is based on your year of birth, as follows:

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.

Clearly, you'll need to know your FRA to determine when the right time is to file for benefits. But in a 2017 Fidelity survey, 74% of Americans shockingly did not know their FRA. If you'd rather your income not take a hit in retirement, commit your FRA to memory and only file for Social Security once you've reached it.

2. Review your earnings record every year

We just learned that your Social Security benefits will be calculated based on your lifetime earnings. But if the Social Security Administration (SSA) has incorrect information about you on file, your benefits could take a hit. Imagine you earned $62,000 during one of your top 35 working years, yet for some reason, the SSA shows no income for you on file that year. It's a strange thing to happen, but it can happen.

That's why you must make a point of checking your earnings record year after year. This way, if you spot an error that works against you, you can report it to the SSA and work on getting it fixed. If you're 60 or older, the SSA will mail you a copy of your earnings statement every year. If you're younger, however, you'll need to create an account on the SSA's website and access your statements there.

3. Fight for higher wages at work

Many workers accept their earnings for what they are and don't advocate for higher wages on their own behalf. The problem, however, is that if your wages remain stagnant for too long, it'll impact not just your near-term financial outlook but your Social Security benefits as well, since those payments correlate directly to how much you earn.

If you've yet to ask for a raise at work but know you're underpaid, you must schedule some time with your manager to have that discussion. But don't just go in blindly. Instead, research salary data for your job title that proves that your wages fall below what the average worker in your field takes in.

Furthermore, go into that conversation armed with a list of ways you consistently add value to your company so that your manager is more motivated to pay you top dollar. Similarly, bring data highlighting the ways you've made or saved your company money to further justify your pay bump. The most important thing, however, is to not shy away from asking for a raise for fear that the conversation won't go well. Otherwise, you'll only be hurting yourself, both now and in the future.

No matter how heavily you come to rely on Social Security in retirement, the higher your benefits are, the more you stand to gain. Take the above steps to protect your benefits, and you'll be happier you did so when you're older.

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