Social Security benefits can be a lifesaver in retirement, especially if your personal savings fall short. But if you depend too much on those checks, it could spell financial disaster during your golden years.

Benefits are designed to replace approximately 40% of your pre-retirement income, and yet nearly half of single beneficiaries and one in five married couples depend on Social Security benefits for at least 90% of their income, according to the Social Security Administration.

Because Social Security benefits are such an integral part of many Americans' retirement plans, it's important to maximize the amount you receive in your monthly checks. Sometimes, even simple Social Security mistakes like these could hurt your chances at retiring comfortably.

Social Security cards stacked on top of each other

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Mistake No. 1: Not knowing your full retirement age

Your full retirement age (FRA) is the age at which you'll receive the full benefit amount you're theoretically entitled to each month. For those born in 1960 or later, your FRA is 67. Those born before 1960 have an FRA of either 66 or 66 and a few months, depending on the exact year you were born.

A whopping 67% of U.S. adults age 50 and over don't know their FRA, according to a survey from Nationwide, yet it can majorly impact how much you receive in benefits. If you start claiming earlier than your FRA, you'll receive a reduction in benefits. But wait to claim until after you reach your FRA, and you'll receive a bonus on top of your full amount, which maxes out when you reach age 70.

You can begin claiming benefits as early as age 62, but by doing so, you could see your benefits reduced by as much as 30%. Typically, these reductions are permanent, too. While it is possible to reverse your decision after you start claiming benefits, you have to do so within 12 months of when you began claiming, and you also have to repay all the benefits you've already received. Once you're outside that 12-month window, you can't make any changes. So if you claim early and then change your mind later, you may be stuck with those smaller checks for the rest of your life.

On the other hand, you can receive extra money each month by delaying benefits until after your FRA -- up until age 70. If your FRA is 67, delaying benefits until age 70 will earn you a 24% boost on top of the full amount you're entitled to.

Mistake No. 2: Assuming it's always better to delay claiming benefits

Since you receive a boost in benefits by waiting to claim, it may seem like a no-brainer to wait as long as you can to receive as much as possible each month. However, that's not always the case. There's no "right" answer as to when you should claim your benefits, and sometimes it's more beneficial to claim sooner rather than later.

Even though you'll see a reduction in benefits by claiming before your FRA, you might still come out ahead financially by claiming early. For instance, if you have reason to believe you won't live until the average life expectancy (around ages 84 and 86 for men and women, respectively), it might be best to claim as soon as you can so you can enjoy your money for as many years as possible. In fact, you might actually receive more over a lifetime by claiming early. Even though you're receiving smaller checks each month, several years' worth of benefits adds up when you claim at age 62 versus age 70.

Also, it pays to be strategic about when you claim if your spouse is also eligible to receive benefits. For example, the lesser-earning spouse may choose to claim benefits early while the higher-earning spouse delays claiming until past his or her FRA. That way, you still have some money to spend early in retirement, but you can also take advantage of those bigger checks for life.

That said, sometimes it is better to delay benefits -- particularly if you expect to spend a very long time in retirement and your savings are sparse. Those bigger checks can potentially save your retirement and make it much easier to enjoy a comfortable lifestyle. But delaying benefits isn't the right choice for everyone, so weigh your options and decide which age is best to claim based on your unique situation.

Mistake No. 3: Not checking your Social Security statements

By checking your Social Security statements, you can get an estimate for what you can expect to receive in benefits based on your real earnings. However, of those who have access to their statements, only 43% check them, according to the SSA.

Seeing how much you can expect to receive once you start claiming your benefits is important because it will impact the rest of your retirement plan. You likely won't be able to depend on your benefits alone to cover all your expenses in retirement, so you'll need some personal savings to fall back on. If you have no idea what you'll receive from Social Security, it's tough to figure out how much you'll need to save on your own.

To check your statements, you'll need to create a my Social Security account. From there, you'll receive an estimate based on your past earnings. Keep in mind this estimate is for your expected full benefit amount -- or the amount you'll receive by claiming at your FRA. If you claim before or after your FRA, that will affect how much you'll receive.

Social Security is an important part of any retirement plan, but to earn as much as possible, you need to be strategic. By understanding how your benefit amount is calculated and what factors influence the amount you'll receive, you can maximize your benefits and enjoy a more comfortable retirement.