How SSDI back pay works
Social Security Disability Insurance (SSDI) pays benefits from your established onset date, after a five-month waiting period. Because approval can take a year or more, most people receive a lump sum of back pay covering the months between when benefits should have started and when they were approved.
The rules the calculator applies
- Five-month waiting period: benefits start with the sixth full month of disability
- Retroactive limit: SSDI pays no more than 12 months before the month you applied
- Representative fee: if you had a lawyer or representative, the fee is usually 25% of back pay, capped at $9,200
SSI is different
Supplemental Security Income (SSI) has no five-month waiting period and no retroactive benefits before the application month. It is needs-based and paid at a federal rate. This calculator covers SSDI.
Check your numbers
Your Social Security statement at ssa.gov shows your estimated monthly disability benefit. The onset date that Social Security accepts can differ from the date you claim, which changes the back pay.
Questions people ask
How long does it take to get SSDI back pay?
Often one to three months after approval, paid as a lump sum to your bank account.
Is SSDI back pay taxable?
Part of SSDI can be taxable depending on your total income. A lump sum can be spread over the years it covers for tax purposes.