A couple of comments:
- Doubtful that Fidelity is going to change anything so I wouldn't get frustrated trying to call them and asking them to send you a corrected form.
- The date issue is not really an issue as either date provides a long-term gain or loss. Just use what is on the 1099-B to avoid any issues.
- You will be able to adjust the cost basis when entering in TT. Make sure you follow the instructions as the software will ask if you need to make any adjustments.
- See the attached instructions to form 8949 and in particular page 8 for the appropriate code that you will need to understand.
- https://www.irs.gov/pub/irs-pdf/i8949.pdf
Taxpayers have adjustments all the time on this form. We aren't able to predict if this will cause any issue, but the key is you need to be able to provide proof of the correct basis if questioned. If you have that, then there will not be any issues.
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
