Retirement tax questions

Because this is a non-covered security (cost basis and/or holding period unknown), you must enter the acquisition date and cost basis from your records  - the program will calculate whether it was a long-tern gain/loss (held 1 year or longer) or a short-term gain/loss (held less than a year)

The 1099-B reported the date sold and the gross proceeds, but not the holding period or cost basis - the brokerage firm doesn't have that information.

See the following sample screenshot for entering this in the "Stocks, Mutual Funds, Bonds and Other" interview.