Do a Search on "itemized deductions" (lower case, no quotes) and jump to it.
Scroll down to the subheading "Other Deductions and Credits", and click on Start for "Other Deductible Expenses".
There are three screens here. Only the third one will put entries on line 16 of Schedule A ("Tell us about your other expenses"). Note that the expenses on the second screen ("Did you have any of these less common expenses?") were eliminated in the Tax Cut and Jobs Act of 2017 and so will not appear on Schedule A.
This means that to put something on line 16 on Schedule A, it needs to be
- Unrecovered investment in annuity
- Claim of right repayment over $3,000
- Estate tax deduction not reported on a K-1
- Ordinary loss attributable to certain debt instruments
- Amortized bond premiums
