You will need to reconstruct the basis paid to the best of your ability. You might consult with your employer's HR department to see about getting some of the records.
Hi,
I reached out to Computershare. They were not very helpful especially regarding the stocks purchased early on in my career.
Only your company may have the full records that you need. Starting in 2011, brokers were required to track the basis for you - for covered shares. You will need to reconstruct your basis. Follow these steps: