Age 70 is hardly the most popular age to sign up for Social Security, namely because it's generally considered the latest age to start collecting benefits. Many seniors don't want to wait that long, so they'll claim their benefits much earlier -- as early as age 62.

It's often said that delaying your Social Security filing until age 70 is a smart move, as it'll help you secure a higher monthly benefit for life. But here's one scenario where it definitely pays to claim benefits well before your 70th birthday.

When your health is questionable

The Social Security benefit you'll be eligible for in retirement is based on your earnings during your 35 most profitable years in the workforce. From there, you'll be entitled to that benefit upon reaching full retirement age, or FRA, which kicks in at 66, 67, or somewhere in between, depending on the year in which you were born.

Person filling out Social Security benefits application form.

Image source: Getty Images.

Meanwhile, you can sign up for Social Security once you turn 62, but for each month you claim benefits before FRA, they'll be reduced on a permanent basis. On the flip side, you can delay your filing past FRA and permanently boost your benefits in the process up until the age of 70. At that point, your benefits won't grow any more.

If you don't have a lot of money in retirement savings, boosting your benefits by claiming them at age 70 may seem like a smart idea. But if you're not confident you'll live a long life, then filing well before the age of 70 makes a lot more sense.

Though claiming benefits early will leave you with less money each month, it may result in more money in your lifetime. If your health isn't great or you have a reason to believe you won't live a very long life, then filing early is your better bet.

Let's imagine you're entitled to a monthly benefit of $1,500 at age 67, your FRA. If you file at age 62, you'll get $1,050 a month instead, whereas if you delay your filing until age 70, your monthly benefit will rise to $1,860.

Cutting a $1,500 monthly benefit down to $1,050 reads like a major financial hit at first glance, especially when you also have the option to turn that $1,500 into $1,860. But let's assume you end up passing away at the age of 73, which is pretty young. In that case, here's what your total lifetime benefit would amount to:

  • $138,600 if you file at 62
  • $108,000 if you file at 67
  • $66,960 if you file at 70

That's why poor health, or concerns about your health, should prompt you to not delay your Social Security filing, but rather, sign up for benefits early. Though it's impossible to predict how long you'll live, if you're not confident in your own longevity, then claiming Social Security well ahead of FRA makes sense.

Does that mean taking the risk that you'll live longer than expected, thereby winding up with a lower lifetime benefit? It does. But think of it this way: If that ends up happening, your consolation prize will be extra years of life. And that's not such a terrible deal.