SSI and SSDI are separate programs with different rules, even though both come from Social Security

Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI) are not the same. Both are run by the Social Security Administration, both require you to have a medical condition that prevents work, and both use the same definition of disability — but they pay different amounts, have different income limits, and serve different groups of people.

The core difference: SSDI is based on your own work history and the taxes you paid into Social Security. SSI is a needs-based program for people with low income and few assets, regardless of work history. A person can receive one, the other, or both at the same time, depending on their situation.

Key Takeaways

  • SSDI requires you to have worked and paid Social Security taxes for a certain number of years; SSI does not require any work history.
  • SSDI has no income or asset limits; SSI limits your countable resources to $2,000 ($3,000 if married) and counts most income against your payment.
  • SSDI payments are based on your earnings record; SSI payments are a flat federal amount that varies slightly by state.
  • You can receive both programs at once if you meet the rules for each, though the total payment is usually capped.

How work history determines which program you can receive

SSDI requires that you worked long enough and recently enough to have built up a Social Security record. The Social Security Administration looks at your age and how many years you worked and paid taxes. Generally, you need 40 work credits, with at least 20 earned in the last 10 years — but the exact requirement depends on your age when you became disabled. A younger person might need fewer credits.

SSI has no work history requirement. You can have never worked, or worked only briefly. SSI is designed for people with disabilities who do not have enough income or assets to support themselves, whether or not they ever paid into Social Security.

If you do not have enough work credits for SSDI, you can still receive SSI if your income and assets are low enough. If you have a strong work history, you will receive SSDI instead, and SSI only if your SSDI payment is very small.

Income and asset limits: SSI has them, SSDI does not

SSDI has no income limit and no asset limit. You can own a house, a car, have savings, and still receive your full SSDI payment. Your unearned income (like interest or rental income) does not reduce your benefit. Your earned income (from work) is counted differently — you can earn some money and still receive most or all of your SSDI payment, depending on how much you earn.

SSI has strict limits. Your countable resources cannot exceed $2,000 if you are single, or $3,000 if you are married. Countable resources include cash, bank accounts, stocks, and some other assets. Your home and one vehicle are not counted. For every $2 in countable resources over the limit, you lose $1 in SSI payment.

SSI also counts income against your payment. The first $65 of monthly earned income is not counted, and half of earnings above that are not counted — but unearned income (like interest, pensions, or help from family) is counted dollar for dollar after a small exclusion. This means receiving money from someone else, or having savings, can reduce or eliminate your SSI payment.

Payment amounts: SSDI is based on your earnings, SSI is a flat amount

SSDI payments are calculated from your lifetime earnings record. The higher your average earnings during your working years, the higher your SSDI payment. Payments range widely — in 2024, the average SSDI payment was around $1,550 per month, but individual payments can be much higher or lower depending on work history.

SSI payments are a federal amount set by Congress, adjusted each year for inflation. In 2024, the federal SSI payment for a single person was $943 per month, and for a couple it was $1,415. Some states add a small supplement on top of the federal amount. Unlike SSDI, your SSI payment does not depend on how much you earned — it depends on your current income and assets.

If you receive both SSDI and SSI, your total payment is usually capped at the SSI federal rate. This means if your SSDI payment is less than the SSI amount, you receive both programs and the total reaches the SSI level. If your SSDI payment is higher than the SSI amount, you receive only SSDI.

Medical requirements are the same for both programs

Both SSDI and SSI use the same definition of disability. Your condition must be expected to last at least 12 months or result in death, and it must prevent you from doing substantial work. The Social Security Administration reviews the same medical evidence and applies the same rules whether you are applying for SSDI or SSI.

The difference is not in the medical standard — it is in who can meet the financial requirements to receive the payment once the medical condition is approved.

Receiving both programs at the same time

You can receive both SSDI and SSI if you meet the rules for each. This usually happens when someone has a strong enough work history to receive SSDI, but their SSDI payment is very low — below the SSI federal rate. Social Security will pay your SSDI first, then add SSI to bring your total to the SSI amount, as long as your income and assets stay within SSI limits.

Once you receive SSDI, you become may be able to access for Medicare after 24 months of receiving payments. SSI recipients receive Medicaid automatically in most states. If you receive both programs, you will have both Medicare and Medicaid.

How to know which program to pursue

If you have worked and paid Social Security taxes, you should apply for SSDI first. SSDI has no income or asset limits, so you will not lose your payment if you have savings or own property. If you do not have enough work credits, or if your SSDI payment would be very low, you can also apply for SSI at the same time.

If you have never worked or worked only briefly, you should apply for SSI. You will need to show that your income and assets are low enough to meet SSI limits. You can apply at your local Social Security office or online at ssa.gov.

Frequently Asked Questions

Can I switch from SSI to SSDI later if I work enough to build credits?

No. Once you stop working due to disability, you cannot build new work credits. However, if you received SSDI in the past and then worked again and paid taxes, you might be able to return to SSDI based on your new work record. Contact Social Security to discuss your specific situation.

If I receive SSI, will I lose my payment if I inherit money?

Yes. Inherited money counts as a countable resource. If the inheritance pushes your total resources over $2,000, your SSI payment will be reduced or stopped. Some people use an inheritance to set up a special needs trust to avoid losing SSI, but you should speak with a benefits counselor before accepting any inheritance.

Do I have to choose one program or the other?

No. You can apply for both at the same time. Social Security will determine which program you may have access to for based on your work history, income, and assets. If you may have access to for both, you will receive both.

Why is my SSDI payment different from my friend's if we both have the same disability?

SSDI payments are based on your individual earnings record, not your disability. Two people with the same condition can have very different SSDI payments depending on how much they earned during their working years. SSI payments are the same for everyone (plus any state supplement), because SSI is not based on earnings.