I have shares in VTI and I'm thinking about selling all my shares, take a loss and turn around the same day and buying the mutual fund, Total Stock Market International Index Fund. Would the IRS consider those two funds substantially identical? Would it be considered a wash sale?

Thanks,
Nick

It's not a wash sale because it's not the same fund. You take a loss on the sale VTI and use those monies to buy TSMIIF and then start over.

The IRS doesn't allow selling and buying back and keeping your old cost basis as much as I'd like to do so. If I could, then the mutual fund company will track my average cost basis for me.

Since they are different equities, selling one and buying the other does NOT meet the definition of a wash sale.

Do it.