Social Security has two programs for people who are disabled: Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI). The programs are different in many ways, but both require that a recipient be disabled. Social Security uses the same definition of disability for both programs: you must have a condition that significantly limits your ability to work and that has lasted or will last at least a year (or will result in death). If you are disabled, the program you apply for will depend on your work history.
When you work, you pay FICA taxes, and part of that money goes to Social Security for you to draw on when you retire or become disabled. That is why SSDI is referred to as a kind of insurance program. Social Security has complicated rules to determine if you have worked enough, and worked recently enough, to qualify for SSDI. There are no income or asset limits to the SSDI program. A person could be a millionaire and still draw SSDI if he were disabled.
If you do qualify for SSDI, the amount that you receive every month depends on your work history. In general, the more income you earned (and paid FICA taxes on) before you became disabled, the higher your SSDI payments will be. That disabled millionaire will get a bigger monthly SSDI check than a disabled millworker (up to a maximum of $2,533 in 2013).
If you have not worked long enough or recently enough to qualify for SSDI, then you might qualify for SSI. SSI does not require any work history and it is not an insurance program that recipients pay into. Instead, it is a type of welfare program that gives a very small monthly benefit to disabled individuals who meet the SSI income and SSI asset tests.
If you are low-income and have few assets, you might qualify for SSI. If you are approved, the amount of the monthly benefit you receive will be the same as other SSI recipients in your state. The federal SSI program pays a set amount each month, and your state may add on an additional amount. The federal base rate for SSI for 2013 is $710 per month.
Other differences between Social Security disability and SSI center around:
Another difference between SSI and SSDI is the type of health insurance available to recipients. SSI recipients qualify for Medicaid. SSDI recipients qualify for Medicare, although federal law currently imposes a two-year waiting period before Medicare eligibility starts.
In general, Medicaid is cheaper to the recipient than Medicare, but Medicare is more widely accepted by health care providers. While there is no premium for Medicare Part A (hospital insurance) for most disability recipients, there are copays and deductibles, and there is a premium as well as copays and deductibles for Medicare Part B (medical insurance for doctor visits, lab costs, and outpatient services). In contrast, federal law requires Medicaid to be free or extremely cheap, so there will be no high prescription costs, copays, or premiums for Medicaid. However, many doctors will not accept Medicaid, while most do accept Medicare.
It is possible, and not uncommon, for a person to receive both SSI and SSDI. Social Security calls that getting "concurrent benefits." If you have not worked much recently, or if you never earned much money when you were working, then the SSDI amount that you qualify for might be less than $710 per month. If so, then you can receive just enough SSI to bring your total monthly income up to $710. If you are in this situation, Social Security will identify your need for concurrent benefits when it gets your disability application.