Can I claim AMT paid on ISO in 2018 on 2021 tax return
I exercised ISO in 2018 and paid AMT, now TurboTax is calculating tax using exercise price as cost basis. I read that I can claim credit for AMT paid in 2018 and have form 6251 but TurboTax is asking for 2020 form. Can I somehow use 6251 form from 2018 return to claim credit on 2021 return?