Correct Cost basis

[ron8]

In 2017 I exercised and held 30,000 shares of stock. I reported it on my tax return and payed taxes on the difference of the price I payed for the stock and the real market value at the time. In 2019 I sold the stock and reported the exercise price as the original price I payed for the stock instead of the real market value (which I believe should be the new price to determine the cost basis and not get double taxed) 

If I did make a mistake, as I believe I did, I will need to amend my return as I filed it and payed too much tax.

Can someone tell me if I am correct and need to amend? Did I report my cost basis wrong?

[Mike9241]

your basis in the stock (assuming you sold all 30K shares) is the income included on your W-2 for the exercise + the cash you paid.  your gain is the difference between what you sold it for and the basis as described above. 

[ron8]

Unfortunately I left that job so none of the proceeds was reported on my W2. To make matters a little quirkier the company I used to work for and whose shares we are taking about got bought and that’s when they settled all the stock that previous employees held. I was payed in two two large chucks in 2019 and a small chunk in 2020 to settle all proceeds. I was doing taxes for 2020 and entering the price I exercised the stock for and thought that I should be entering the real market value assed in 2017 not just the price I originally paid when I acquired. If I entered the original price the cost basis that TurboTax comes up with is only the price I payed and doesn’t take into account the gains I was taxed on in 2017 when I exercised and held.

So if I am correct I did my taxes wrong in 2019 as I reported the price as the original price I payed and not the real market value that would have become my “new” price when figuring out my capital gains.