The 35-Year Earnings Average That Could Cost You $240,000 in Social Security Benefits

Two retirees with similar lifetime earnings walk away with vastly different Social Security checks. One receives about $4,152 a month. The other gets closer to $3,349. The gap traces to one formula line: Social Security averages your highest 35 years of inflation-adjusted earnings, and any year you missed counts as a zero. Across a 25-year retirement, this difference compounds into roughly a quarter million dollars.

How the 35-year average moves the number

Social Security pulls your top 35 years of earnings, adjusts each for wage inflation, divides by 420 months, and calculates your Average Indexed Monthly Earnings (AIME). That AIME runs through a three-step formula with two bend points that determine how much of each slice gets replaced. In 2026, those thresholds are $1,286 and $7,749. The benefit replaces 90% of AIME up to the first bend point, 32% up to the second, and 15% above it.

Compare two workers claiming at the full retirement age (FRA) of 67 in 2026.

Worker A spent 35 years at or above the wage cap, which sits at $184,500 in 2026. Their benefit lands at the statutory maximum, $4,152 a month.

Worker B earned $120,000 a year for 30 years, then took five years off for caregiving, a layoff, and a sabbatical. Those years may not have produced any earnings but they still count in the average. The AIME comes to about $8,571 a month. Run through the bend point formula, the monthly benefit is roughly $3,349.

Same lifetime dollars on paper. Roughly $800 a month less for life. After cost-of-living adjustments (COLAs) compound over 25 years, the gap widens past $1,000 a month in later years, and the lifetime total approaches $240,000. With the Consumer Price Index (CPI) reaching 3.8% year over year in April 2026, the highest reading in nearly three years, each annual COLA enlarges the dollar gap between the two benefits a little further.

This dominates other Social Security decisions because it shapes the base benefit. Claiming age moves the percentage. The 35-year average moves the dollar figure that gets multiplied. A claiming choice can be revisited within 12 months. A year of zeros stays put unless you cover it with later earnings.

Where this lands in retirement spending

An $800 monthly gap shows up everywhere. Healthcare premiums, property taxes, and groceries do not care which career pattern you had. Healthcare spending alone reached $3,741.3 billion on an annualized basis as of March 2026, and costs keep climbing. The lower-benefit retiree typically draws more from a 401(k) or IRA to maintain the same lifestyle, which accelerates required minimum distributions (RMDs) at age 73 and can push more of the Social Security check into taxable territory.

One underused fix exists. Working a 36th or 37th year, even part time, replaces a low or zero year in the average. A self-employed consulting year at $40,000 in your late 60s can lift the AIME enough to recover $50 or $100 a month for life. Multiply that by 240 months of retirement, and you see the impact.

What to do with this

Pull your earnings record at ssa.gov/myaccount once a year. Look for issues like missing years, employer reporting errors, and your running count of years on the books. If you see fewer than 35, you know exactly how much room you have to replace zeros with current, often higher, wages.

Two takeaways:

1. If you took years off for caregiving, illness, school, or a layoff, plan to work past the year you “could” retire. Each added working year at decent pay upgrades your benefit for the rest of your life without requiring investment skill or market timing.
2. The hardest mistake to undo is assuming Social Security only rewards peak earning years. It rewards your top 35, and zeros stay in the average unless you cover them with later work. Once you start benefits, the door on filling those years closes for good.

Every situation has its own variables, including pensions from non-covered employment, spousal and survivor rules, and state taxes on retirement income. Run your own numbers against your actual earnings statement before drawing firm conclusions, because a single missing year on the record can be worth more than most claiming strategies people debate online.