Will I have to file taxes if I didn't work in 2023, due to cancer?

[xmasbaby0]

So sorry about your health issues.   If you did not have taxable income during 2023 you do not have to file a tax return unless you have a 1095A for health insurance from healthcare.gov and need to enter the premium tax credit you have been getting from the marketplace.

Who has to file?

http://www.irs.gov/uac/Do-I-Need-to-File-a-Tax-Return%3F

[Opus 17]

It's not the work, it's the income.  If you withdrew money from an IRA, 401k, or other retirement plan, or if you cashed in stocks or other investments, that income will be taxable and you must file to report it.  You would get tax statements from the various brokers or businesses (1099-INT, 1099-DIV, 1099-R, 1099-B, or others), usually by February 15.