Your Social Security benefits are calculated based on your earnings during your 35 highest-paid years in the workforce, but you're not entitled to your full monthly benefit until you reach full retirement age, or FRA. FRA hinges on your year of birth, as follows:

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

1960 or later



Here's the problem: In a recent MassMutual survey of near-retirees aged 55 to 65, 31% said that FRA kicks in at age 65, regardless of year of birth. And that's a misconception that could wind up hurting anyone who believes that.

Older man scratching his head


Your filing age matters

You're allowed to claim Social Security prior to FRA, but for each month you do, your benefits get reduced by a certain percentage. The earliest age you can sign up for benefits is 62, and not surprisingly, it's also the most popular age to file. But claiming benefits at 62 with an FRA of 66 will result in a 25% reduction in your monthly Social Security income. Filing at 62 with an FRA of 67 will produce a 30% cut.

Now, if you think your FRA is 65 when it isn't, and you claim Social Security then, you could wind up with anywhere from a 6.67% to a 13.34% reduction in your monthly benefits, depending on your precise FRA. And while a lower monthly benefit may not be such a big deal if you're sitting pretty in the retirement savings department, many seniors are behind in that regard, and, as such, need all of the Social Security income they can collect. That's why it's important to know your correct FRA -- and use it to guide your filing decision so you don't short yourself on benefits for life.

Don't confuse Social Security and Medicare

One reason why so many older Americans may be confused about 65 being their FRA is that Medicare eligibility begins at 65. But while the two programs are interrelated, you can sign up for one without the other. That means you can claim Social Security before age 65, albeit at a reduced monthly benefit rate, or you can sign up for Medicare at 65 and hold off on filing for Social Security until FRA or even beyond. That's right -- you can delay your benefits past FRA and boost them by 8% a year in the process, up until age 70, at which point that incentive runs out.

Get your facts straight

The more you know about Social Security, the more likely you are to file for benefits at the right time for you. If you're among the 31% of Americans who think FRA is 65 across the board, it could be an indication that you're lacking key knowledge about the program on a whole, so spend some time reading up on Social Security to avoid mistakes that hurt you on a long-term basis.