SSDI is taxed exactly the same as Social Security retirement benefits. There is no distinction in TurboTax because there is no distinction in the tax law. I don't know where you got the impression that they are treated differently.
@arcticranger wrote:
Does TT automatically detect and calculate the correct percentage that is taxable?
Yes, you enter the full amount from box 5 of your Form SSA-1099. TurboTax automatically calculates the taxable amount. On Form 1040 the total amount that you received is on line 6a and the taxable amount is on line 6b. You can see the calculation on the Social Security Benefits Worksheet.
