Your Illinois income includes the adjusted gross income (AGI) amount figured on your federal return, plus any additional income that must be added to your AGI. Some of your income may be subtracted when figuring your Illinois base income.

Schedule M, Other Additions and Subtractions for Individuals, allows you to figure the total amount of additions you must include on Form IL-1040, Individual Income Tax Return, Line 3 and subtractions you may claim on Form IL-1040, Line 7.

You may not subtract anything that is not listed on Schedule M. For example, you may not subtract

  • unemployment compensation. Unemployment compensation included in your federal adjusted gross income, except railroad unemployment, is fully taxable to Illinois.
  • gambling losses. Illinois does not allow a deduction for gambling losses.
  • your federal itemized deductions from U.S. 1040 Schedule A, Itemized Deductions.
  • any wages reported on your federal return. If you believe the wages reported on the Form W-2, Wage and Tax Statement, you received from your employer are incorrect, you must obtain a corrected Form W-2 or a statement from your employer, on company letterhead, stating that your Form W-2 was incorrect. We will not accept a letter from you or your tax preparer.