I am a retired Illinois teacher, living in Illinois. My friends tell me that I do not have to file an Illinois tax return. Is this true?

[HelenaC · Accepted solution]

No, that is not necessarily true.  Illinois law states, as an Illinois resident, you must file Form IL-1040:

• If you were required to file a federal income tax return, or
• If you were not required to file a federal income tax return, but your Illinois base income from Line 9 of your Form IL-1040 is greater than your Illinois exemption allowance.  

Per IL Department of Revenue, http://tax.illinois.gov/TaxForms/IncmCurrentYear/Individual/IL-1040-Instr.pdf Retired Illinois resident who filed a federal return, must file Form IL-1040. However, certain types of retirement income (e.g., pension, Social Security, railroad retirement, governmental deferred compensation) may be subtracted from your Illinois income. For more information, see the instructions for Line 5 and Publication 120, Retirement Income, http://www.revenue.state.il.us/Publications/Pubs/Pub-120.pdf