If you’re planning to take Social Security in 2025, you’re likely nearing retirement. While that’s an exciting chapter in life, even small mistakes can sometimes throw a wrench in your plans — so it’s critical to ensure you have a strong plan heading into your senior years.

There’s not necessarily a right or wrong Social Security strategy, but there is one aspect that trips many retirees up: knowing how your claiming age will affect your lifetime benefit.

Your benefit will be locked in for life

The age you file for benefits will have an immediate and lifelong impact on your benefit amount. However, many people are unaware of just how much their decision will affect their monthly income.

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According to a 2025 survey from the Nationwide Retirement Institute, only 21% of U.S. adults can correctly name their full retirement age (FRA) — which is the age at which you’re entitled to your full benefit based on your work history. Your FRA will depend on your birth year, but everyone’s will fall between ages 66 and 67.

Filing before your FRA will result in a reduced payment, which is also a point of confusion for many people. The survey found that 40% of Americans believe that if they file for benefits early, their payments will automatically go up once they reach their FRA. In reality, though, these reductions are permanent, and those smaller payments will be locked in for life.

These reductions can be significant, too. If you have an FRA of 67 years old, filing at 62 will slash your checks by 30%. The average retired worker receives around $588 less per month at age 62 compared to age 67, according to 2024 data from the Social Security Administration.

Data source: Social Security Administration. Table by author.

Not knowing exactly how your age will affect your lifetime benefit amount is a simple mistake to make, so you’re in good company if you’re among the 40% of Americans in this boat. But if you’re heading into retirement expecting your benefit to increase by hundreds of dollars per month in a few years, it could be a costly mistake.

The best move you can make right now

Before you begin claiming benefits, one of the best things you can do is check your estimated benefit amount.

You can do this by reviewing your statements through your mySocialSecurity account online, where you’ll see an estimate of your future benefit based on your real earnings. This is also a prime opportunity to double-check that your earning history is correct, because if there’s any information missing or incorrect, it can affect your benefit amount.

The estimate you see on your statements is your full benefit amount, or the payment you’ll receive by filing at your FRA. From there, you can determine exactly how your claiming age will affect the size of your checks.

Data source: Social Security Administration. Table by author.

You can also file for benefits at any age between birthdays, but for every month you claim before your FRA, your benefits will be reduced slightly more. By having at least a rough estimate of how much will be deducted, it will be easier to plan accordingly.

Keep in mind, too, that if you’re filing after your FRA (up to age 70), that will also alter your benefit. If you have an FRA of 67 and you file at 70, you’ll collect your full benefit, plus a bonus of 24% per month.

There’s no right or wrong time to take Social Security, but it is important to know how that decision will affect your benefit. When you know what to expect from Social Security heading into retirement, you can rest easier knowing you’re as prepared as possible.