Do I need to report a 1099-B transaction which has nothing listed in box 1e for cost or other basis, the basis was not reported to IRS, and it is a noncovered security?

[cdedelman]

I am not sure it is possible to compute an exact cost basis because I was having dividends from a tiny amount of shares continually reinvested over a period of 11 years going back to November 2005.  Also, Box/Code X is checked, indicating "unknown holding period."

[Anita01]

Yes, you do have to report the sale.  I would expect you would be receiving at least an annual statement showing each year's dividend reinvestment and you could add those to your original cost to arrive at a total cost.  You would need to break out the amount of shares purchased through the reinvestment within the 12 months before sale and allocate all the rest to being long-term, meaning a purchase date more then 12 months before the sale.  It only matters that it be more than 12 months before sle.

If the proceeds are a very small amount, you can always just use zero as the cost and pay tax on the full proceeds.  You could mark it all short-term if yoou don't mind paying the tax.