I have one sale of a security where my broker did not enter the cost basis; both proceeds and basis say "0." I have entered the correct cost basis, so as to record the loss on this investment. But I am wondering if there is anything else I need to alter to make it clear the info on my brokerage forms is wrong? Right now the sale category says "Box D - long term covered." Should I change this to "Box F - long term unreported" since my broker did not report the basis? Or should I just manually change the basis and leave everything else like it is?
Since you've adjusted the basis, leaving "Long-term basis reported to IRS (covered)" in the Sales section box on the Now, enter one sale on your [security] 1099‑B screen is fine.
You typically don't want to change what's on an information return such as a Form 1099-B. Adjustments to cost bases are fairly common, but changes to the category reported on a 1099-B, much less so. There's no reason to raise a red flag when you're doing everything correctly.
Since you've adjusted the basis, leaving "Long-term basis reported to IRS (covered)" in the Sales section box on the Now, enter one sale on your [security] 1099‑B screen is fine.
You typically don't want to change what's on an information return such as a Form 1099-B. Adjustments to cost bases are fairly common, but changes to the category reported on a 1099-B, much less so. There's no reason to raise a red flag when you're doing everything correctly.