Supplemental Security Income (SSI)   The Supplemental Security Income (SSI) program makes cash assistance payments to aged, blind and disabled people including children under the age of 18 who have limited income and resources.  Cash payments paid by the federal government are known as the Federal Benefit Rate.  In addition to the federal benefit rate some states offer a cash supplement.  The Federal Benefit Rate for the year 2008 is $634 per month for an individual and $956 per month for an eligible couple. Social Security will base your payment on the amount of other income that you receive, you're living arrangement, and the state in which you live.  To figure your SSI payment amounts Social Security starts with your federal benefit rate, adds your state supplement, if any, and subtracts your countable income. Social Security does not count all the income that you have.  For example, they do not count any part of a scholarship or grant that you used to pay for tuition, books, or related educational expenses.  A house and a primary car used for transportation of the person with the disability is not counted as a resource. Medicaid is a jointly funded federal-state health insurance program for low income and needy people.  It covers children, the aged, blind, and/or disabled and other people who are eligible to receive federally assisted income maintenance payments. There is no waiting period required before receiving SSI benefits.  Your payments will start as soon as Social Security is able to decide if you meet that eligibility requirements.  If your state does not require a separate application for Medicaid, your Medicaid eligibility starts the same month as your SSI eligibility. According to Social Security's Redbook, to be eligible for SSI based on a medical condition you must meet the following criteria: You must have little or no resources or income; You must be a U.S. citizen or meet the requirements for non-citizens; You must be considered medically disabled; You must be a resident of the 50 states, District of Columbia, or Northern Mariana Islands; You must file an application; You must file for any and all other benefits for which you are eligible; and You must accept vocational rehabilitation services, if referred; and if your impairment is other than blindness, when you apply, you must not be working or working but not performing substantial gainful activity. If you are blind, only the first seven requirements apply to you. How the Social Security defines disability? Both SSDI and SSI defined disability as the inability to engage in any Substantial Gainful Activity (SGA) because of a medically determined physical or mental impairment that can be expected to result in death, or that has lasted for, they can be expected to last for a continuous period of not less than 12 months.