Income tax rates The Indiana Individual adjusted gross income tax rate for 2026 is 2.95% and will adjust in 2027 to 2.90% . County income tax rates may be adjusted in January and October. Departmental Notice #1 contains the most recent county income tax rate chart for withholding. The current year IT-40 Income Tax Instruction Booklets contain the most recent rates for individual filers. Historical rates for residents are available in prior year IT-40 Income Tax Instruction Booklets . Nonresident rates for 2016 and earlier are available in prior year IT-40PNR Income Tax Instruction Booklets.