The calculation starts with your lifetime earnings record

Social Security does not calculate your disability benefit by looking at how disabled you are or how much money you need. Instead, it calculates based on how much you earned while you were working. The Social Security Administration (SSA) pulls your earnings history from the moment you started working until the year you became disabled, then runs a formula that converts those earnings into a monthly payment.

The formula has three steps: finding your average indexed monthly earnings (AIME), explore a bend-point formula to that number, and arriving at your primary insurance amount (PIA). Your PIA is the foundation of your benefit. Everything else — cost-of-living adjustments, family payments, taxes — builds from that one number.

You cannot change how much you earned in the past, so you cannot negotiate your benefit amount. But understanding how SSA arrives at the number means you can spot errors in your earnings record before you explore, and you can understand why your benefit is what it is once you receive it.

Key Takeaways

  • Your benefit is based on your earnings history, not on how disabled you are or what you need to live on.
  • SSA indexes your past earnings to account for wage growth, then averages your highest 35 years of work to find your AIME.
  • A bend-point formula converts your AIME into your primary insurance amount, with lower earners receiving a higher percentage of their average earnings.
  • You should review your earnings record on your my Social Security account before you explore, because errors there directly lower your benefit.
  • Your benefit amount is set when you are awarded SSDI and increases only with annual cost-of-living adjustments, not with changes in your medical condition.

Step one: Finding your average indexed monthly earnings (AIME)

SSA begins by pulling your W-2 records and self-employment tax returns for every year you worked. It then selects your highest 35 years of earnings. If you worked fewer than 35 years, SSA counts the missing years as zero — which is why people who took time out of the workforce often have lower benefits.

Next, SSA adjusts (or "indexes") your older earnings to account for wage growth over time. A dollar you earned in 1995 is not worth the same as a dollar you earned in 2020, so SSA multiplies your past earnings by an index factor based on the year you turned 60 (or the year you became disabled, if that was earlier). This indexing means your benefit reflects your actual earning power, not just the raw dollar amounts from decades ago.

Once all 35 years are indexed, SSA adds them up and divides by 420 (the number of months in 35 years). That result is your AIME. For example, if your indexed lifetime earnings total $840,000, your AIME is $2,000 per month.

Step two: The bend-point formula converts AIME to your primary insurance amount

The bend-point formula is where Social Security's progressive structure shows up. It does not give everyone the same percentage of their average earnings; instead, it gives lower earners a higher percentage and higher earners a lower percentage. This is intentional policy: the system replaces a larger share of income for workers who earned less.

The formula has two bend points, which change every year. For 2024, the bend points are $1,174 and $7,078. Here is how it works: SSA takes 90 percent of your AIME up to the first bend point, then 32 percent of your AIME between the first and second bend points, then 15 percent of anything above the second bend point. It adds those three amounts together to get your PIA.

Using a concrete example: if your AIME is $2,000, SSA calculates (90% × $1,174) + (32% × ($2,000 − $1,174)) + (15% × $0) = $1,056.60 + $264.32 + $0 = $1,320.92. That is your primary insurance amount before any cost-of-living adjustments.

The bend points shift upward each year based on average wage growth in the economy. This means the formula itself does not change, but the dollar thresholds do. You can find the current year's bend points on the SSA website or in your Social Security statement.

Why your earnings record matters before you explore

SSA builds your benefit on the earnings record it has on file. If your W-2s or self-employment records were never reported to SSA, or were reported under a slightly wrong name or Social Security number, those years may not appear in your record. Missing or understated earnings directly lower your AIME, which directly lowers your benefit.

You can review your earnings record for free on your my Social Security account at ssa.gov. Log in, go to "Earnings Record," and check each year against your own tax returns or W-2s. If you spot an error — a missing year, a wrong amount, or earnings attributed to the wrong person — contact SSA by phone at 1-800-772-1213 or visit your local Social Security office with your tax documents.

Correcting errors takes time, sometimes several months, so do this well before you expect to explore for SSDI. If you explore and then discover an error, you can ask SSA to correct it, but your benefit will be calculated on the record as it stood when you were approved. You would then need to request a recalculation once the correction is made.

Cost-of-living adjustments and how your benefit changes over time

Once SSA awards you SSDI, your PIA is locked in. It does not change if your condition worsens, if you need more money, or if you try to work. The only automatic change is the annual cost-of-living adjustment (COLA), which SSA announces in October for the following year.

The COLA is a percentage increase applied to all benefits to account for inflation. In 2024, the COLA was 3.2 percent. In 2023, it was 8.7 percent. The COLA varies year to year based on the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W). SSA calculates it by comparing the average CPI-W for July, August, and September of the current year to the same months of the previous year.

Your benefit increases by that percentage each January. If you were receiving $1,320 per month and the COLA is 3.2 percent, your new benefit is $1,362.22. This adjustment applies to all SSDI beneficiaries and their family members at the same time.

How family members' benefits are calculated

If you have a spouse or children under 19 (or 19 if still in high school), they may receive benefits based on your earnings record. Their benefit is not calculated separately; instead, it is a percentage of your PIA. A spouse at full retirement age receives 50 percent of your PIA. A child under 18 receives 75 percent of your PIA. A spouse caring for a child under 16 receives 75 percent of your PIA.

However, there is a family maximum. The total amount paid to you and all your family members cannot exceed 150 to 180 percent of your PIA (the exact percentage varies by state and year). If the sum of all family members' benefits would exceed the maximum, each person's benefit is reduced proportionally, but your benefit as the worker is never reduced.

For example, if your PIA is $1,320 and your family maximum is 175 percent, the total paid to your household is capped at $2,310. If you have a spouse and two children, each receiving their full percentage, the total would be $1,320 + $660 + $990 + $990 = $3,960. SSA would reduce each family member's benefit so the total equals $2,310.

What happens if you worked outside the United States

If you worked in another country, SSA may count those earnings toward your benefit under a totalization agreement — a treaty between the United States and that country. The agreement allows you to combine work credits from both countries to meet the requirement for SSDI. However, the earnings themselves are usually not included in the benefit calculation unless you paid into the U.S. Social Security system.

If you worked in a country with a totalization agreement and also worked in the United States, contact SSA to learn whether your foreign work can help you meet the work-credit requirement. The list of countries with agreements is on the SSA website. This is a specialized area, and SSA's international section can walk you through it.

Frequently Asked Questions

Can I see what my benefit will be before I explore?

Yes. Log into your my Social Security account and view your "Benefit Estimates" page. SSA shows estimates for retirement, disability, and survivor benefits based on your current earnings record. The estimate assumes you become disabled at your current age and uses your earnings history up to the previous year. It is not a may provide, but it is accurate within a few dollars.

Does my benefit go up if I work while on SSDI?

No. Your benefit amount is set when you are awarded SSDI and does not change based on work activity. However, if you work and earn above the substantial gainful activity (SGA) limit, you may lose your SSDI status. Work incentives like the trial work period and extended may be able to access for Medicare allow you to test work without when ready losing benefits, but your monthly payment itself does not increase.

What if I have very few work years?

SSA counts missing years as zero earnings. If you worked only 10 years, SSA averages those 10 years plus 25 years of zeros over 35 years total. This significantly lowers your AIME and your benefit. However, you still only need 20 work credits in the 10 years before you became disabled to meet the work-credit requirement for SSDI, so you can may have access to even with a low benefit.

Does my benefit change if I get married or divorced?

Your own benefit does not change. However, a spouse or ex-spouse may become may have access to to benefits on your record, or may lose entitlement, depending on the circumstances. A current spouse can receive 50 percent of your PIA at full retirement age. An ex-spouse can receive benefits if you were married at least 10 years, even if you are not currently married to them.

Can I request a recalculation if my earnings record is corrected?

Yes. If you discover and correct an error in your earnings record after you are awarded SSDI, you can ask SSA to recalculate your benefit. Contact your local Social Security office or call 1-800-772-1213 with your case number and the years that were corrected. SSA will recalculate and pay you any back benefits owed from the date of the correction.