Millions of seniors collect Social Security, and those benefits enable them to stay afloat financially in retirement. If you're nearing that milestone, you may be wondering whether your enrollment in Social Security will be automatic or whether you'll need to actively sign up for benefits. The answer is most certainly the latter.

You get choices

Unlike Medicare, which begins at age 65, there's more than one age at which to start collecting Social Security. You actually get an eight-year window to file for benefits that begins at age 62 and ends at 70.

Smiling older woman using laptop.

IMAGE SOURCE: GETTY IMAGES.

In the middle of that period is full retirement age, otherwise known as the age at which you're entitled to collect your full monthly benefits based on your earnings history. That age hinges on the year you were born, 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.

The advantage of waiting until full retirement age to sign up for benefits is that you won't face a reduction in your monthly payments. Signing up at any point prior, on the other hand, will slash your benefits, most likely for life. That said, if you need the money sooner, you can sign up at age 62 and get your hands on that income.

On the other hand, if you don't need your benefits by the time full retirement age rolls around, you have the option to hold off on benefits past that point. For each year you do, you'll accrue delayed retirement credits that boost your benefits by 8% a year, up until age 70, at which point that incentive runs out.

What happens if you don't sign up for Social Security by the time your 70th birthday rolls around? Even though there's no financial benefit to waiting past 70, enrollment still isn't automatic at that point. If you don't arrange to get benefits by age 70, you'll risk losing out on income that's rightfully yours (though keep in mind that Social Security will pay you up to six months of retroactive benefits, so if you're not signed up by age 70 but correct that mistake soon after the fact, you could conceivably be made whole).

The point, either way, is that the Social Security Administration can't determine when you're ready for benefits and therefore can't just sign you up automatically. Only you can make that decision.

When should you sign up for Social Security?

The decision to claim Social Security should be based on a number of factors, including your age, your need for the money, and your work status. You're allowed to work and collect benefits simultaneously, but if you do so before reaching full retirement age, you'll risk having some benefits withheld if your earnings exceed a certain limit.

Another thing to keep in mind is that it can take the Social Security Administration a little time to process your application for benefits. As such, it pays to sign up a couple of months before you actually want to start collecting those payments. For example, if you're planning to wait until age 70 to start taking benefits, you may want to enroll when you're 69 and 10 months.

Most of the time, signing up for benefits is a quick, easy process. You can enroll online or do so in person at a local Social Security office if you prefer.