Entering 1099-B Type of Gain or Loss

[dooalot]

How do I know whether it was short term or long term gain when the sale category is "Box X - unknown holding period?"

[RichardG]

The gain/loss is long term if the investment was held for more than one year.  Any holding period less than that is short term gain/loss.  Please review your brokerage statements or contact your brokerage firm for the purchase information.