There's a worksheet in 1040 Tax Form Instructions for SSDI benefits (form 1099?) to see if your SSDI is taxable or not. I have never made enough on SSDI to pay any taxes and I get $1450/mth from SSDI. (There's probably also a 1099 worksheet on IRS webpage to figure it out. I think you divide SSDI total by 2 then subtract your exemption from it and if that # is below a certain amount then you don't need to pay any taxes. Something like that.)

If you owe $0 you still have to file and your payment or amount owed will be $0.

I think this is the worksheet -
http://www.irs.gov/publications/p915/ar02.html