In 2020, did you pay any expenses that: Were used to maintain investments that are exempt from federal tax, but are taxable to Illinois? what does this mean?

Items such as investment fees or transaction fees would be items considered as expenses to maintain your investments.

 

Sometime investments are not taxable for federal purposes but are taxable within your state.  That would make them taxable within Illinois but not on your federal return.  

 

I have attached a link with a bit more detail as to what type of income is taxable and not taxable as it does vary based upon your investment.

 

Interest income from US obligations

Any ideas on how or where to locate the amount of the expenses? 

It depends.

 

Assuming you have investments in a brokerage account, for example, you would find expenses such as these listed on your year-end statement.  

 

If you paid an investment advisor, it could be located on their year-end statement or in your account summary online depending upon how your activity is reported to you.