How do I enter a Put (Option) transaction in TT? It's entering a Zero cost basis trade, which doesn't seem to be correct.

[Mike9241]

a put option for a stock - if you first bought it that's its cost and if you sold it that's its sales price. if it expired the sales price is zero - so you have a capital loss.

if you first sold it that's its sales price and if you purchased it to closed that's its cost. if it expired the cost is zero - so you have a capital gain.

if the option is still open at year-end, then there's nothing to report until the year you close the position or it expires. 

did you get a 1099-B? if so, then look at what it shows to make sure your entries match the tax form