What Is the Difference Between Social Security Disability (SSDI) and SSI?

Both SSI and SSDI disability programs offer cash benefits for disabled individuals, but the financial eligibility requirements are very different.

By , Attorney · UC Law San Francisco

The main difference between SSDI (Social Security Disability Insurance) and SSI (Supplemental Security Income) is the fact that SSDI is available to workers who have collected a sufficient number of work credits over the years to be considered "insured" for the program. SSI disability benefits are available to low-income individuals who have either never worked or who haven't earned enough work credits to qualify for SSDI.

Here are a few more key differences between the two programs:

  • SSDI usually pays higher benefits than SSI. The average SSDI payment is about $1,500, while the average SSI payment is only about $700 per month.
  • The SSDI program can pay benefits to cover the time before you applied. If you're found disabled, SSI payments can only start as early as the first full month after you filed your claim. But SSDI payments can start earlier, up to a year before you apply.
  • Approval rates are higher for SSDI than SSI. In most, but certainly not all cases, individuals who are eligible for SSDI receive more medical treatment than those eligible for SSI only, which makes it easier for SSDI claimants to prove disability. Also, judges often give more credibility to applicants who have a long work history than those who don't.

While many people don't distinguish between SSI vs. SSDI, they are two completely different governmental programs. Both programs are overseen and managed by the Social Security Administration (SSA), and the SSA determines medical eligibility for disability the same way for both programs, but there are distinct differences between the two programs.

SSI benefits are also known as Title 16 disability benefits (or Title XVI benefits), named after that section in the Social Security Act, and SSDI benefits are also known as Title 2 benefits (or Title II benefits).

What Is Supplemental Security Income (SSI)?

SSI provides minimal basic cash assistance to disabled individuals with little recent work experience. The SSI program was created when states' welfare programs for the blind, disabled, and elderly were federalized. SSI disability benefits are not paid out of the Social Security Trust Fund, but out of general funds, and it falls under Title 16 of the Social Security Act.

To qualify for SSI, you must have a very limited income (or no income) and less than $2,000 in assets (or $3,000 for a couple).

Technical requirements for SSI. Unlike the SSDI program, you don't need to have a certain amount of work history for SSI. If you meet the income and asset limits, you financially qualify for the program. Of course, you must also prove that you medically qualify by proving that you're disabled.

How much does SSI pay? The amount of SSI that an eligible person will receive is dependent on the amount of regular, monthly income they have and where they live. (SSI recipients who get free room and board, say at a friend's house, get a lower benefit. Also, some states pay a higher supplemental payment to some SSI recipients.) The maximum federal SSI payment is $943 in 2023 ($1,415 for couples).

When does SSI start? SSI benefits will begin on the first of the month after the month in which you submit your application.

What other benefits are available? Disabled people who are eligible under the income requirements for SSI are also able to receive Medicaid in the state they live in. Most people who qualify for SSI also qualify for food stamps. SSI is paid out of general funds of the U.S. Treasury, much like other safety net programs.

Who gets SSI? SSI applicants are somewhat more likely to be female, as fewer women are eligible for SSDI benefits (about 71% of women compared to 79% of men). Women generally have fewer qualifying years of work (over 60% of men have worked at least part of every year of their adult life, while only 41% of women can say the same).

Learn more about the SSI program and SSI benefits.

What Is SSDI?

SSDI is a federal insurance program that gives cash benefits to disabled workers. SSDI benefits are paid out of the Social Security Trust Fund; about 15 cents of every Social Security tax dollar goes toward the disability trust fund rather than the retirement trust fund. Also known as DIB, or Disability Insurance Benefits, SSDI is covered under Title 2 of the Social Security Act.

SSDI recipients are considered "insured" because they've worked for quite a few years and have made contributions to the Social Security trust fund in the form of FICA Social Security taxes (or SECA self-employment taxes). SSDI benefits are closely tied to Social Security retirement benefits; SSDI is essentially a form of early retirement for those who become disabled before age 65 (and the monthly benefit is the same).

Technical requirements for SSDI. SSDI candidates must be younger than 65 and have earned a certain number of "work credits." (To learn more, see our article on SSDI and work credits.)

When does SSI start? SSDI applicants have a five-month waiting period for benefits, meaning that the SSA won't pay benefits for the first five months after someone becomes disabled. But SSDI recipients can get retroactive payments going back to a year before their application date.

How much are SSDI payments? The amount of your monthly SSDI benefit after the waiting period is over depends on your earnings record, much like the Social Security retirement benefit. The maximum SSDI benefit in 2024 is $3,822, but very few people get this amount.

What other benefits are available? After receiving SSDI for two years, a person with a disability becomes become eligible for Medicare. (Applicants with ALS, or Lou Gehrig's disease, are eligible for Medicare as soon as they're approved for SSDI.)

Who gets SSDI? Under SSDI, a disabled person's spouse and child dependents are eligible to receive spousal benefits and dependents benefits, called "auxiliary benefits." But children with disabilities can't receive SSDI on their own; only adults over the age of 18 can receive SSDI disability benefits, and only if they've worked for several years.

What are the chances of getting approved for SSDI? Approval rates for SSDI are higher on average than they are for SSI. There are a number of possible reasons for this, including:

  • SSDI applicants are more likely than SSI applicants to have higher income and insurance coverage, which means they're more likely to see a doctor for their medical problems. (It's very difficult to win disability without seeing a doctor regularly.)
  • Judges and claims examiners give more credibility to applicants who have a long work history, which most SSI applicants don't have.
  • SSDI applicants are more likely to hire legal professionals to help with the application or hearing, which can double someone's chances of getting benefits.

Learn more about the SSDI program and SSDI benefits.

Can I Collect Both SSDI and SSI at the Same Time?

You can collect SSDI and SSI at the same time if you're approved for SSDI but your SSDI payment is low. This might be the case if you made low wages over the years or you didn't work much in recent years. If your SSDI payment is less than $963 (or $1,435 for a couple), you could get a small SSI payment in addition to your SSDI payment, to raise it up to the SSI amount.

But you still have to meet the SSI requirements to receive concurrent benefits, so if you have more than a thousand or two in cash or countable assets, or income other than SSDI, you won't qualify. But again, the definition of medical disability is the same for both programs, so it's easy to qualify medically for both at the same time.

When you get SSDI and SSI at the same time, it's called receiving "concurrent benefits." You receive two different checks, on different payment dates for SSDI and SSI.

You don't have to request concurrent benefits when you apply for disability. If your income, including your anticipated SSDI payment, is less than the federal benefit rate, Social Security will automatically consider your application for SSI.

Medicare vs. Medicaid Benefits

If Social Security finds you disabled and you qualify for SSDI, you'll receive Medicare benefits two years after you start receiving SSDI benefits (or two years from the date you should have started receiving benefits, if your case took a long time to process).

In contrast, if Social Security finds you disabled and you're eligible to receive SSI benefits, you can receive Medicaid benefits immediately. In some states, you need to file a separate application for Medicaid, but in others, your disability application will be a combined application for SSI and Medicaid.

Ask a claims representative at your local Social Security office whether you have to file anything to receive Medicaid in your state. For more information, see our article on Medicaid and Medicare for disability recipients.

How Do I Apply for SSDI or SSI?

If you're applying for Social Security disability insurance (SSDI), you can file your whole claim online on Social Security's website.

If you're applying for SSI, you can get started on Social Security's website, but you won't be able to file the entire application online unless you're also applying for SSDI at the same time.

If you can't file online, or you're not comfortable online, call Social Security at 800-772-1213 to start your claim. For more information on applying for either SSDI or SSI, see our article on applying for Social Security disability benefits.

Should I Get Professional Help?

If you need help filing an application for SSDI or SSI, or you want to appeal a denied claim, contact an experienced disability representative to discuss your options. Disability attorneys and advocates almost always offer free consultations, and don't charge a fee unless you win your case.

According to a survey of our readers, applicants who filed an initial application without help were denied 80% of the time. Getting help at the initial application stage gives you a good chance of getting benefits in just three or four months. That's because a legal professional can help you complete your initial application for benefits in a way that's accurate but persuasive. On the other hand, if you think you have a very strong case, you could apply on your own and then hire legal help if you're denied benefits.

Updated December 29, 2023

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