Many seniors look to Social Security to provide the bulk of their retirement income. Some go so far as to get all of their income from Social Security.

But despite the important role the program plays in many people's retirement, it seems like the public lacks Social Security knowledge in a very disturbing way. Recently, only 1% of respondents ages 55 to 65 were able to ace a quiz on Social Security basics administered by MassMutual. Meanwhile, 65% of respondents either failed or got a D grade, while 18% earned a C.

No matter what role you expect Social Security to play in your retirement, it's important to have a solid understanding of how the program works. Here are three key points to keep in mind.

Social Security cards.

Image source: Getty Images.

1. Benefits are earnings-based

Social Security doesn't pay all seniors the same benefit. Rather, the monthly benefit you're entitled to will hinge on your personal earnings history. Social Security takes your 35 highest-paid years of income into account when calculating your benefits, so if you don't work a full 35 years, you will end up with a lower monthly payday.

2. Your filing age matters

You're entitled to your complete Social Security benefit based on your earnings history at full retirement age. However, you're allowed to claim benefits sooner than that.

The earliest you can file for Social Security is age 62. But if you go that route, you'll reduce your monthly benefit for life. Technically, you get one chance to undo an early filing in your lifetime. But for many seniors, that isn't feasible. So if you claim benefits early, it's best to assume that the reduced payment you end up with will be the payment you continue to collect throughout your retirement.

You can also delay your filing past full retirement age. For each year you do, up until age 70, your benefit gets a permanent 8% boost.

3. Full retirement age isn't universal

Some people assume they're entitled to their complete Social Security benefit at age 65, since that's when Medicare eligibility begins. But actually, full retirement age for Social Security doesn't begin until age 66 at the earliest, and it's also not the same for everyone. Rather, it depends on your year of birth. You can consult this table to see what your full retirement age looks like:

Year of Birth

Full Retirement Age




66 and 2 months


66 and 4 months


66 and 6 months


66 and 8 months


66 and 10 months



Data source: Social Security Administration.

If your goal is to avoid any sort of reduction in benefits, then it's important to know your precise full retirement age. Claiming Social Security at 66 versus 67, for example, could result in a 6.67% hit to your benefits, which could really add up to a lot of lost money over time.

Get your facts straight

There's a good chance you'll rely on Social Security to some degree once you leave the workforce, so it pays to learn as much about the program as you can. Doing so could help ensure that you get more money from Social Security -- and avoid filing mistakes that could leave you cash-strapped throughout your senior years.