If you received the payout in 2018 then you will have to report the payout on your 2018 tax return.
If the payout was received in 2019 you can wait and report the payout on your 2019 tax return.
You will report the transaction using Form 1099-B file your tax return.
[Edited 03/10/2020 | 7:59 am PDT]
