The Most Important Social Security Rule No One Talks About

Millions of people have a retirement plan that depends on Social Security. But a little-known rule could determine how much you actually receive in benefits each month.

This key factor is the Social Security Administration's (SSA) 35-year work requirement. Knowing how it works can help you make smarter decisions, whether you plan to retire early or work late into your career.

How are Social Security benefits calculated?

Social Security benefits are based on your average indexed monthly earnings (AIME), which comes from your 35 highest-earning years.

The Social Security Administration adjusts past earnings for inflation, totals earnings from your top 35 years, and divides the figure by the total number of months in those years to find your AIME.

That number is then used in a formula to determine your primary insurance amount (PIA), which is the basis for the benefits you receive.

What happens if you don't work for 35 years?

Many people focus on when to claim Social Security benefits, but fewer understand how many years they need to work to earn the maximum payout. This knowledge gap can cost you a lot of money throughout retirement.

If you work less than 35 years, the SSA still calculates your AIME over 35 years by adding zeros for the years you did not work. Each zero drags down your average, lowering your monthly benefit for life.

For example, if you work only 30 years, the SSA will add five zero-earning years into the formula.

This rule is why part-time work or staying with your main job for a few extra years late in your career can make a noticeable difference in your Social Security payout. Even replacing a low-earning early career year with a higher-earning later year can help boost your benefit.

Who is most likely to fail to work 35 years?

Certain groups may be more likely to fall short of the mark of working 35 years. Parents, especially mothers, who take extended time out of the workforce to raise children may have gaps in earnings.

People who retire early by choice — or who are forced to stop working due to illness, disability, or family responsibilities — may also be at risk of missing the threshold.

Additionally, some self-employed workers or those with irregular work histories may have years with lower or no reported earnings, which can count as zero years in the SSA's calculation.

Recognizing these risks early allows you to take steps to fill in the gaps before you claim benefits.

How can you boost your benefit later in life?

If you have fewer than 35 years of earnings, the simplest way to improve your benefit is to keep working and earn extra income. Every additional year of income can replace a zero year in the formula.

So, even part-time work at a decent wage can make a difference if it replaces a zero or a low-earning year.

You can also delay claiming your benefit until full retirement age, or even later. For each year after full retirement age and up to age 70 you wait, you increase your monthly benefit by roughly 8%.

This strategy, combined with replacing low-earning years, can significantly raise your lifetime payout.

Ways to boost savings if your Social Security benefits are low

If your benefits will be lower due to working fewer than 35 years, boosting your savings in other ways can help to shore up your finances.

In addition to taking on part-time work or simply working longer, you can also increase your retirement savings contributions.

For example, increase retirement account contributions by taking advantage of catch-up contributions if you are age 50 or older. The 2025 limit for 401(k) account contributions is $23,500 for most folks, but catch-up contributions add an additional $7,500 for those age 50 and older.

In addition, those who are between the ages of 60 and 63 can add an extra $11,250 in catch-up contributions.

Building up your savings can help you get ahead financially and offers a cushion if your Social Security check will be smaller than you would like.

Bottom line

Social Security's 35-year work rule might be the most important retirement planning factor no one talks about. If you have fewer than 35 years of earnings, zeros will be factored into your benefit calculation, permanently lowering your payout.

Knowing this rule gives you time to plan, fill in gaps, and supplement your Social Security income so you can fully enjoy your golden years with fewer financial worries.