Turning 66 in 2026? 1 Important Thing to Know About Social Security.

People have a tendency to celebrate big birthdays like 60 and 65. People's 66th birthdays might sometimes get swept under the rug. But 66 has long been a big deal to older Americans for one key reason -- it long signified the go-ahead to sign up for Social Security.

For many years, age 66 was full retirement age for Social Security purposes. And full retirement age is when you can claim your monthly benefits without a permanent reduction.

Image source: Getty Images.

But if you're turning 66 in 2026, you may not want to sign up for benefits just yet. That's because you won't be reaching full retirement age. And if you claim benefits next year, they'll be reduced on a permanent basis.

You can't get your full Social Security benefits just yet

Age 66 was full retirement age for Social Security for people born between 1943 and 1954. For people born in 1955 or later, full retirement age has gradually increased. And for those born in 1960 or later, full retirement age is 67.

This means that if you're turning 66 in 2026, you will not be able to claim Social Security without a reduction. That's an important thing to keep in mind if you'll be relying heavily on those monthly benefits to supplement your retirement savings, or perhaps make up for a lack of savings.

Of course, this doesn't mean you can't sign up for Social Security in 2026. Those benefits become available once you turn 62.

However, if you file for benefits before reaching full retirement age, they'll be reduced on a permanent basis. And depending on your financial situation, you may not be able to afford that.

Granted, if you claim Social Security one year ahead of full retirement age, your benefits will be reduced by about 6.67%. That's not the most extreme reduction.

But still, the less money you get from Social Security each month, the more reliant you might be on your savings or other income streams. And if you'd rather lock in a guaranteed larger benefit, then waiting for full retirement age to arrive makes sense.

You may want to hold off even longer

Although you can collect your Social Security benefits without a reduction at full retirement age, you should also know that for each year you delay your claim beyond that point, your monthly benefits increase 8%. That boost could be a lifeline if your IRA or 401(k) balance leaves much to be desired and you're worried you won't get very much money out of your savings each year.

Now the delayed retirement credits you get for waiting on Social Security do run out at age 70. So if your full retirement age is 67, the maximum boost you can get is 24%. But that's still nothing to scoff at.

Also remember that Social Security benefits are eligible for an annual cost-of-living adjustment. The more money you get in your monthly benefits to begin with, the more value those raises should have for you.

Of course, the downside of claiming Social Security at 70 is that you may have to work longer in order to pull off a delayed filing. But that sacrifice may be worth it if it eliminates a good amount of financial worry throughout your senior years.

All told, it's important to time your Social Security claim carefully. That means understanding when your full retirement age will arrive and figuring out what an early or late filing might mean for your monthly checks. The more thought you put into your filing decision, the more likely you are to choose the age that's best for you.

The Motley Fool has a disclosure policy.