The federal SSI monthly payment standard will increase from $637 to $674 for an individual, $956 to $1,011 for a couple. This means that an SSI recipient can receive more income (earned or unearned) before benefits will be terminated.
Social Security Administration (SSA) estimates that the average SSDI payment will increase from $1,006 in 2008 to $1,064 this year.
The threshold for substantial gainful activity (SGA) for SSDI will increase from $940 to $980. If an individual's income is such that thethreshold amount is exceeded then SSDI benefits are typically lost.
Also, in 2009 students who receive SSI will be able to exclude up to $6,600 of annual income if they are regularly attending school. This figure is up from $6,240 last year.
All the details on these cost-of-living adjustments are here.