Millions of workers approaching retirement are carrying the wrong number in their heads, and most of them have no idea.

Social Security’s full retirement age has been climbing gradually for more than two decades, and in 2026, it reached its final destination. If you were born in 1960 or later, your full retirement age is now 67, and that number will not move again.

The Social Security Amendments of 1983 set this whole process in motion, raising the full retirement age from 65 in increments of two months per year beginning with people born in 1938.

The logic was straightforward: As life expectancy rose, the program needed adjustments to stay solvent over the long term. What Congress passed more than 40 years ago is only now completing its full effect, and the people it hits hardest are those who assumed the rules they heard about years ago still apply.

Also read: Warren Buffett sees a retirement problem getting harder to ignore

If you are already collecting benefits or already past full retirement age, nothing about your situation changes. But if you were born in 1960 or later and have not yet filed, the finish line just moved.

The gap between when you can first claim and when you can claim without penalty is now five years, and the cost of miscalculating that gap follows you for life.

What the full retirement age actually does

Think of full retirement age as a dividing line.

Cross it and you collect what Social Security calculated as your full benefit. File before you get there and the agency trims your monthly check permanently, with no correction once you have locked in. Hold off past FRA and your benefit keeps climbing through delayed retirement credits, up to age 70.

The SSA calculates FRA based on birth year. Workers born between 1955 and 1959 had a full retirement age that ranged from 66 years and two months to 66 years and 10 months, depending on the specific year they were born.

Workers born in 1960 or later all land at 67. That is the ceiling, and there is no further increase scheduled beyond it.

Take someone born in 1960. Their full retirement age lands in 2027, and any month they file before that date costs them on the monthly benefit. The cut is baked in from the moment they file and does not adjust upward when they eventually turn 67.

Millions of workers approaching retirement are carrying the wrong number in their heads, and most of them have no idea.

bankerwin / Getty Images

Claiming Social Security at age 62 is riskier than it used to be

The option to claim at 62 has not gone away, but what it costs you to use it has grown.

When the full retirement age was 65, claiming at 62 meant filing three years early. With FRA now at 67, the same 62-year-old is filing five years early, and the benefit reduction reflects that larger gap.

For workers with a full retirement age of 67, claiming at 62 can cut the monthly benefit by as much as 30%.

There is also a break-even calculation involved. Taking a reduced benefit for more years only comes out ahead if you do not live long enough to recoup the gap through higher payments later.

Someone who expects to live well into their 80s is likely better served by waiting. Someone with serious health concerns may find that the earlier, smaller check adds up to more over their actual lifetime.

Waiting past FRA, on the other hand, adds roughly 8% per year to your monthly benefit for every year you hold off between FRA and 70. Three full years of credits are available after FRA, and after 70 there is nothing additional to gain.

Health, other income sources, expected longevity, and what a surviving spouse might need later all factor into the right answer, but none of that calculation works without the correct FRA as a starting point.

Why working and collecting at the same time can cost you

Some people file early and keep working, figuring they can collect and earn at the same time. Social Security’s retirement earnings test complicates that plan. It withholds a portion of benefits any year your earnings exceed a set threshold, and it only kicks in before you have reached full retirement age.

File at 62, stay employed until 67, and you are sitting in that window for five straight years.

More Social Security:

  • Social Security’s next COLA could erode on arrival
  • Social Security’s estimator makes one costly assumption
  • Social Security’s biggest check locks out most retirees

The money withheld does come back eventually. At full retirement age, Social Security bumps up your monthly payment to account for the months that were held back, and the check adjusts upward from there.

Getting to that point, though, means years of collecting less than your full amount, and plenty of people filing early are not aware of how the earnings test works until after they have already signed the paperwork.

What to do before you file

A Nationwide survey found that only 21% of Americans can correctly identify their full retirement age. That figure is striking, given how much money rides on that single number.

Getting it wrong does not just affect one paycheck. It recalibrates every payment for the rest of retirement.

Before filing anything, log into your My Social Security account at SSA.gov. The portal shows your complete earnings history and projects your estimated monthly benefit at 62, at full retirement age, and at 70.

Differences between those three numbers can easily run into hundreds of dollars a month, and over a 20- or 30-year retirement, that gap becomes a very large sum.

If you are married, the decision extends beyond your own benefit. The monthly amount you lock in at filing becomes the basis for survivor benefits, which means a lower benefit for you can translate into a lower benefit for your spouse for years or decades after you are gone.

Benefits are also taxable above certain income thresholds, and Medicare premiums can adjust based on your income from prior years, so the net value of a monthly check depends on more than just the gross amount.

The full retirement age has been 67 on the books since 1983. For people born in 1960 or later, 2026 is the year that number finally became theirs.

Related: Social Security announces new cost-of-living adjustment for 2027