Are you talking about SSI or SSDI? SSI would be absolutely no work. For SSDI you must prove that you are not engaging in any Substantial Gainful Activity, meaning you cannot make more than $960 a month. But, it does raise a red flag even if you were only making $500 even though it's not supposed to. Getting a letter from your employer saying they've made special accomodations for you might help. (Like being allowed to work only on your "good days" as an example.)


Substantial Gainful Activity

To be eligible for disability benefits, a person must be unable to engage in substantial gainful activity (SGA). A person who is earning more than a certain monthly amount (net of impairment-related work expenses) is ordinarily considered to be engaging in SGA.

The amount of monthly earnings considered as SGA depends on the nature of a person's disability. The Social Security Act specifies a higher SGA amount for statutorily blind individuals; Federal regulations specify a lower SGA amount for non-blind individuals. Both SGA amounts increase with increases in the national average wage index.

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.

http://www.ssa.gov/OACT/COLA/sga.html