As a retiree, Social Security will probably provide a lot of your income. It's also an income source experts have classified as ideal because it's guaranteed for life, and checks increase periodically so it maintains its buying power. Because of this, you need to understand factors that affect your checks, and one of the most important is the age when you file for benefits.

You could choose to start getting benefits as early as 62, or could claim any time between 62 and 70. But for many people, 66 is the right age. That's because for anyone born between 1943 and 1954, 66 is considered to be your full retirement age. 

When you're deciding whether to claim Social Security at 66, you need to know what it means for that age to be your full retirement age. And unless you're turning 66 this year, you also need to understand that FRA is changing, so starting benefits at 66 may not make as much sense for anyone born after 1954. 

Older couple reviewing financial paperwork with an advisor.

Image source: Getty Images.

Is 66 your full retirement age?

Workers who pay into Social Security have a standard benefit amount, which is the amount they'll receive if they retire at full retirement age (FRA). FRA is set by law.

When the Social Security benefits program was first established, FRA was set at 65. But in 1983, the law was amended to gradually move FRA to 67. It doesn't jump up in one big jump, though. Instead, it's gradually increased over time. 

For everyone born between 1943 and 1954, FRA was moved to 66 from 65. If your FRA is 66, you can claim benefits at that age to receive your standard benefit. However, if you haven't yet turned 66 and you won't until 2021 or beyond, your FRA will be later. If you file for benefits at 66 with a later FRA, you'd face early filing penalties. If you were born in 1955 and your FRA is 66 and two months, you'd face two months of early filing penalties if you start benefits at 66.

The table below can help you determine when you'll hit your FRA based on your birth year, so you can see what age you need to file to receive your standard Social Security benefit. 

If you were born in:

Full retirement age for you is:

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

Does it make sense to file at 66, file earlier, or wait to claim your benefits?

If 66 is your full retirement age, it can make a lot of sense to claim benefits at that age. That way, you can avoid the reduction in benefits resulting from early filing.

While you won't earn delayed retirement credits you could've received if you waited to start getting retirement benefit checks until after FRA, you also won't need to worry about whether you'll live long enough for future higher checks to make up for income you miss out on by waiting. 

But if 66 isn't your FRA, you may want to wait a bit. 

Claiming benefits at 66 can make a lot of sense if you'll hit that milestone this year

If you're turning 66 this year, taking your Social Security now can make a lot of sense, since it's when the Social Security Administration set your standard retirement age. But if you'll turn 66 in 2021 or beyond, you may want to think about waiting until you hit your FRA to avoid an early filing penalty. 

Ultimately, the choice depends on you. But since your benefits will be important to your retirement security, don't claim them until you've done the research and know how your age when you start benefits will affect your monthly income.