According the Social Security Administration, to be eligible for disability benefits, you must be unable to engage in substantial gainful activity (SGA). If you are earning more than a certain monthly amount you will most likely be considered to be engaging in SGA.
The amount of monthly earnings considered as SGA will depend on the nature of your disability and whether or not your are blind. The Social Security Act specifies a higher SGA amount for statutorily blind individuals; federal regulations specify a lower SGA amount for non-blind individuals.
SGA earning limits increase with the increses in the national average wage index.
SGA Amounts for 2009
The monthly SGA amount for statutorily blind individuals for 2009 is $1,640. For non-blind individuals, the monthly SGA amount for 2009 is $980. SGA for the blind does not apply to Supplemental Security Income (SSI) benefits, while SGA for the non-blind disabled applies to Social Security and SSI benefits.