IL 2021 joint elderly 119Kswages 57Kintrec 19Kgssi 3Kproptax

See http://taxsim.nber.org/out2psl/1172

TA does not include the property tax portion of the rebate in the value reported for srebate. It appears to me that PE accounts for the property tax credit of $71 for this taxpayer, but the 20221-2022 rebate includes the same amount again. See https://www.illinois.gov/news/release.html?releaseid=25425

which includes this:

The State of Illinois is also providing property tax rebates for eligible homeowners in an amount equal to the property tax credit they qualified for on their 2021 returns, up to a maximum of $300. The rebate is not allowed if a taxpayer’s adjusted gross income for the taxable year exceeds $500,000 for returns with a federal filing status of married filing jointly, or $250,000 for all other returns.

So I think the rebate should be $171 rather than $100.

Start with the TAXSIM output at http://taxsim.nber.org/out2psl/1172 and compare the srebate value with the Illinois release linked in the issue. Trace the Illinois 2021–2022 property-tax rebate calculation and verify the reported rebate includes the $71 property-tax portion exactly once, producing $171 rather than $100.