Federal SSI benefits are paid at different rates depending on whether you have an eligible spouse and whether you have an "essential person" (see §2110):
If you do not have an eligible spouse - you are due the FBR of $637 per month in 2008, provided you have no countable income; or
If you are an eligible couple - You are due the FBR of $956 per month in 2008, provided you have no countable income.
Both of these rates are established in the Social Security Act, and are subject to annual cost-of-living adjustments (COLA's). The COLA increases the FBR effective in January based on the increase in the Consumer Price Index.
Last Revised: Feb. 1, 2008
Social Security Handbook