If your only source of income is SSDI, then you need not file with IRS. A small amount of money from interest on bank accounts will not change that situation. However if you have other substantial sources of income, then you may have to file, using the ordinary 1040 forms. For example, if you owned a two-flat, living in one unit and renting out the other one, you have the rental income and will need to file with IRS. If you are married and your spouse has income, then you jointly (unless a tax advisor suggests otherwise), indicating your SSDI income.I suggest working with a CPA to learn what applies to your particular situation, especially if your disability income comes from a different source than Social Security, or the amount is higher than what Social Security might pay.