The 1099-b that I received from E*trade for my RSUs showed 0 for the cost basis. That’s what I reported in TurboTax and as I result I owed and paid much more taxes than expected. I read online that sometimes brokers don’t report the correct cost basis so I looked at the tax documents in my E*trade account and found a Supplemental Information document that shows the adjusted cost basis for the RSUs that vested last year. Should I have reported this adjusted cost basis and is this a valid reason to amend my 2023 tax return?
