Ok, I made a lengthy reply somewhere on here. when you make the initial entry, on the first screen where you make the entry, there is a "Does any of the following apply" and one of the options is "proceeds are from a qualified opportunity zone fund." Ok, this is worded weird using the word "from" but YOU HAVE TO CHECK THAT BOX or you will not get CODE Z in the drop down menu on the subsequent screens. I hope you can find my detailed reply where I explained it screen by screen. It was a royal pain in the butt.
