In my case, the corrected 1099 DIV is from a tax year two years ago - 2021. It corrected the basis for a sale of non-covered shares of a gifted mutual fund in 2008 from $0 to $9252.99. However, when I filed the return 2 years ago, I reported the cost basis as $11,900 which resulted in a larger reported loss. I have supporting year end documentation from Vanguard that shows the basis was $11,900. At the time of the sale (done over the phone with an agent), I specified the particular lot I wanted to sell. Will there be any consequences if an amended return is not filed?
