ESPP sold without cost basis

[bmshah1]

I had bought some shares for my employer through the ESPP. The company then later split into two publicly traded companies. One of these two companies then also spun off another publicly traded company. The ESPP acquisition date that is shown on my 1099 is before all this activity happened.

Last year I sold stocks in all the 3 companies at the same time. I bought the original shares in my ESPP over a decade ago. How do I know what my cost basis is for each of these 3 companies?

[ThomasM125]

Your cost basis is what you paid for the stock when you originally acquired it plus this discount on the shares you acquired (the fair make value less what you paid for the shares.) The discount should be reported on your W-2 form in the year the stock is sold as an increase in your wages reported in box 1, over what your normal wages were for the year. It may also be reported in box 14 on your W-2 form. 

The cost basis and discount would be reported on Form 3922 you would have received in the year you acquired the stock. If you don't have that or other records that provide the cost information you can request your employer give you an accounting. Otherwise, you will have to research historical stock prices online to get an estimate of what you may have paid for the shares.