SSDI Calculator

Social Security Disability Insurance is not a welfare program. It is insurance you bought with the Social Security tax on every paycheck, and the benefit is calculated from your own earnings history with the same formula that sets retirement benefits. The difference is timing: SSDI pays the full formula amount as soon as you qualify, at any age, while retirement benefits are reduced if you claim before full retirement age. If you want the retirement side of the same formula, the Social Security Calculator runs it with claiming-age adjustments. This page focuses on the questions that only come up with a disability claim: how much you will get, how much back pay is owed, what your family receives and whether you have enough work credits.

What SSDI pays and who qualifies

To receive SSDI you need two things. First, a medical condition that meets SSA's strict definition of disability: you cannot do substantial work because of it, you cannot do your past work or adjust to other work, and the condition has lasted or is expected to last at least 12 consecutive months or to result in death. There is no benefit for partial or short-term disability. Second, you need enough recent work covered by Social Security, measured in work credits.

SSDI is different from Supplemental Security Income (SSI). SSI is a needs-based program with strict income and asset limits, and it does not depend on your work history. SSDI has no asset test at all, and your payment depends only on your past covered earnings. In August 2026, SSA paid about 6,975,000 disabled workers an average of $1,635.90 a month, and the spouses and children on their records received averages of $463.94 and $529.79.

The 2026 SSDI benefit formula

Your SSDI benefit is your primary insurance amount. SSA builds it from your AIME, the average of your wage-indexed monthly earnings over your computation years, in three slices separated by the 2026 bend points:

The bend points belong to your year of eligibility, which for a disabled worker is the year the disability begins. They rise most years with the national average wage index, so a disability that began in 2025 uses the 2025 bend points of $1,226 and $7,391, and the resulting PIA has then been raised by the 2.8% cost-of-living adjustment paid from January 2026. The calculator applies the 2026 formula, which is exact for disabilities beginning in 2026 and a close estimate for the years just before.

The formula is deliberately progressive. Every dollar of AIME up to $1,286 adds 90 cents to your benefit, but each dollar above $7,749 adds only 15 cents. The table shows what that means at common earnings levels, along with the family maximum explained further down.

Two patterns stand out. At an AIME of about $1,400 or less, 85% of AIME is below the PIA, so the family maximum equals the PIA and a low earner's spouse and children receive nothing on the record. And between $4,000 and $12,000 of AIME the benefit rises by only $1,837.40 while AIME triples, which is why SSDI replaces a much smaller share of pay for higher earners.

Worked example 1: AIME of $4,000 with a spouse and two children

Maria's AIME is $4,000. The first slice is 90% of $1,286 = $1,157.40. The second slice is 32% of the $2,714 between $1,286 and $4,000 = $868.48. Nothing falls above $7,749. The total of $2,025.88 is rounded down to the dime, so her PIA is $2,025.80 and her monthly payment is $2,025, or $24,300 a year.

Her husband cares for their two children, ages 6 and 9, so he and each child can receive up to 50% of her PIA, $1,012.90 each. The family maximum caps that. It is the larger of 85% of her AIME ($3,400.00) or her PIA, but no more than 150% of her PIA ($3,038.70), so the cap is $3,038.70. Subtracting Maria's own $2,025.80 leaves $1,012.90 for the three of them, $337.60 each, paid as $337. The household receives $2,025 + 3 × $337 = $3,036 a month.

Her disability began on January 15, 2026, she applied in February and was approved in October. February is her first full month of disability, so the waiting period runs from February through June and her first month of benefits is July, paid in August. That matches the example in SSA's own disability booklet. Back pay covers July, August and September: 3 × $2,025 = $6,075 for Maria and 3 × $1,011 = $3,033 for her family, $9,108 in total. With a representative under a fee agreement, the fee would be 25% of that, $2,277. Her Medicare coverage begins in July 2028, after 24 months of entitlement.

Worked example 2: a late application and the 12-month limit

James has an AIME of $2,500: 90% of $1,286 = $1,157.40, plus 32% of $1,214 = $388.48, for a PIA of $1,545.80 and a monthly payment of $1,545. His disability began in November 2023, but he did not apply until September 2025. The waiting period cannot begin earlier than the 17th month before the application month, which is April 2024, so it runs from April through August 2024 and his benefits begin in September 2024, exactly 12 months before he applied.

His claim was approved in June 2026 after a hearing. Back pay runs from September 2024 through May 2026: 21 months × $1,545 = $32,445. A representative's fee would be 25%, or $8,111.25, which is below the $9,200 cap. Had James applied in time, his waiting period would have run from December 2023 and his benefits would have started in May 2024, four months and $6,180 earlier. Those months are lost for good. (To keep the arithmetic simple, this example uses the 2026 formula and the 2026 amount for every month. SSA would apply the 2023 bend points of his eligibility year, add the cost-of-living adjustments since then and pay each past month at the amount in effect at the time.)

If James has one child under 18, the family maximum shows its other side. Eighty-five percent of his AIME is $2,125.00, which is less than 150% of his PIA ($2,318.70), so the cap is $2,125.00. After his own $1,545.80, his child can receive $579.20, paid as $579, instead of the full 50% rate of $772.90.

How SSDI back pay is calculated

Back pay, which SSA calls past-due benefits, is the sum of all monthly benefits you were entitled to before your claim was decided. Four rules determine it:

• Waiting period. The first five full calendar months of disability are never paid. A month counts only if you were disabled for all of it, so a disability that begins on the 1st counts that month; one that begins on the 15th does not.
• Entitlement month. Benefits start with the month after the waiting period. SSA pays each month's benefit in the following month.
• Retroactivity limit. The waiting period cannot begin earlier than the 17th month before the month you apply, so benefits never start more than 12 months before your application.
• Cutoff. Past-due benefits run up to, but not including, the month of the favorable decision. From then on you receive regular monthly payments.

The table applies those rules to five timelines at a benefit of $2,025 a month. The fee column shows the most a representative can charge under a fee agreement: 25% of past-due benefits, up to $9,200.

The first two rows differ only in the day the disability began, and the 1st of the month is worth a whole extra month. The last two rows show the fee cap at work, and the very last row shows a late application cutting months of benefits off the front of the claim. These are simplified figures: SSA pays each past month at the amount in effect then, and the 2.8% COLA raised payments from January 2026.

Work credits: the recent-work and duration tests

You earn up to four Social Security credits a year. In 2026 each credit takes $1,890 of wages or self-employment income, so $7,560 earns all four for the year. SSDI applies two tests at once. The duration of work test asks whether you worked long enough: take the year your disability began and subtract the year you reached 22, with a minimum of 6 credits. The recent work test asks whether you worked recently enough, and its rule depends on your age when the disability began. Workers who are statutorily blind only need to pass the duration test.

The ages are the age reached in the year the disability began. Between 25 and 30 the recent-work rule counts the quarters since the quarter after you turned 21 and requires credits in half of them, so the exact number depends on your birthday; the "about" figures assume the disability began in your birthday quarter. Because the recent-work window moves forward every quarter, a person who stops working can lose SSDI protection about five years later even with 40 credits on record.

Benefits for your spouse and children

Family members can be paid on your record while you receive SSDI: a spouse of any age who cares for your child under 16 or disabled, a spouse 62 or older, and unmarried children under 18, under 19 if still in high school, or any age if disabled before 22. Each can receive up to 50% of your PIA. A spouse who is 62 to 66 and has no child in care is reduced for age: 25/36 of 1% for each of the first 36 months before full retirement age and 5/12 of 1% for each month beyond, so at 62 the reduction is 35% and the benefit is 32.5% of your PIA.

The disability family maximum is stricter than the one for retirement and survivor benefits. SSA takes 85% of your AIME, uses your PIA instead if that is larger, and caps the result at 150% of your PIA. Your own benefit is never reduced. Your family members share whatever is left between the cap and your PIA, in equal shares. A divorced spouse who was married to you for at least 10 years can also qualify at 62, and that payment does not count against the family maximum or reduce anyone else.

Working while applying or receiving SSDI

Earnings matter twice. While your claim is pending, work that pays more than the substantial gainful activity level, $1,690 a month in 2026 (or $2,830 if you are blind), usually ends the claim at the first step, before your medical records are even reviewed. After approval, SSA's work incentives let you test a return to work: any month with earnings above $1,210 counts as a trial work month, and you can use nine of them within a rolling 60-month period while your benefits continue. Report all work to SSA promptly, because benefits paid for months you were not entitled to must be repaid.

How to use this calculator

1. Earnings record: enter your AIME if SSA has given it to you, the disability amount from your Social Security Statement, or your current salary for a rough estimate. The Statement figure is the most reliable number most people have.
2. Family members: choose whether a spouse qualifies and how many eligible children you have. The calculator applies the family maximum and any age reduction for a spouse.
3. Back pay timeline: pick the month your disability began, tick the box if it began on the 1st, and enter the months you applied and were (or expect to be) approved. Tick the ALS box if that applies.
4. Eligibility checks: enter your age, your total credits and your recent credits from your Statement, plus any current earnings, to see both credit tests and the SGA check.

Results update instantly: the monthly benefit at the top, the formula steps, the family table, the back pay timeline with the representative fee cap, and the eligibility checks.

Who this calculator is for

It is built for people deciding whether and when to apply, for claimants waiting months or years for an initial decision or a hearing who want to know what back pay to expect, and for family members working out what a household will live on. Representatives and caseworkers can use the timeline to explain to a client why the first five months are unpaid and how a late application shortens a claim. Planners can use the family table to see how much of a household's income replacement SSDI really covers, and whether savings such as an emergency fund need to bridge the waiting period.

Key terms

• AIME: average indexed monthly earnings, your career earnings adjusted for national wage growth and averaged over your computation years.
• PIA: primary insurance amount, the formula result and the amount SSDI pays.
• Bend points: the AIME thresholds where the formula rate drops from 90% to 32% to 15%; $1,286 and $7,749 in 2026.
• Established onset date: the date SSA decides your disability began, which may differ from the date you give.
• Waiting period: the first five full calendar months of disability, for which no benefit is paid.
• Past-due benefits: benefits owed for months before the decision month, commonly called back pay.
• Family maximum: the cap on total monthly benefits paid on one worker's record.
• SGA: substantial gainful activity, the monthly earnings level SSA treats as substantial work.
• Trial work period: nine months of work above $1,210 (2026) that do not end your benefits.

What changes your SSDI amount, and the limits of this estimate

• Your earnings history. Years with low or no earnings pull your AIME down, which is why the salary estimate can overstate the benefit for someone with gaps in work.
• Your year of eligibility. Earlier years used lower bend points, offset in part by the cost-of-living adjustments added since.
• Cost-of-living adjustments. Each December benefits rise by the COLA; the latest was 2.8%.
• Other disability payments. Workers' compensation and some public disability benefits can reduce SSDI.
• Taxes and Medicare premiums. Part of SSDI can be taxable at higher household incomes, and Medicare Part B premiums are deducted once Medicare begins.

This calculator does not decide whether you are disabled, does not read your earnings record and does not model SSI, which many people receive alongside or instead of SSDI. Use it to understand the rules and to check SSA's figures, and rely on your award letter for the official amount.

Related calculators

• For benefits paid to a family after a worker's death, use the Survivor Benefits Calculator.
• For your retirement benefit at ages 62 to 70 from the same formula, use the Social Security Calculator.
• To find the full retirement age when SSDI converts to retirement, use the Retirement Age Calculator.
• To apply a cost-of-living adjustment to your monthly check, use the COLA Calculator.
• To estimate how many years of benefits to plan for, use the Life Expectancy Calculator.
• To fit a disability income into monthly spending, use the Budget Calculator.

Sources

• SSA, Primary Insurance Amount: the 2026 formula, bend points of $1,286 and $7,749, rounding to the dime.
• SSA, Benefit Formula Bend Points: bend points by year of eligibility, including 2025.
• SSA, Substantial Gainful Activity: $1,690 and $2,830 a month for 2026.
• SSA, Trial Work Period: $1,210 a month in 2026; nine months within a rolling 60-month period.
• SSA, Quarter of Coverage: $1,890 per credit in 2026.
• SSA, Contribution and Benefit Base: the $184,500 taxable maximum used to cap the salary estimate.
• SSA, Latest Cost-of-Living Adjustment: 2.8% from December 2025 benefits.
• SSA, Disability Benefits: How Does Someone Become Eligible?: definition of disability, waiting period, 12 months of retroactive benefits, the 20/40 rule.
• SSA Publication 05-10029, Disability Benefits (July 2026): recent work and duration of work tests, family benefits, Medicare after two years, no waiting period for ALS.
• Social Security Act, section 223: definition of the waiting period and disability insured status.
• 20 CFR 404.403: the disability family maximum.
• 20 CFR 404.1703: definition of past-due benefits.
• SSA, Fee Agreements: the lesser of 25% of past-due benefits or $9,200 for favorable decisions issued on or after November 30, 2024.
• SSA, Monthly Statistical Snapshot, August 2026: average benefits of disabled workers and their families.