Can I use prior year earned income to calculate the Earned Income Credit for 2021?
According to the 2021 1040 Instructions, earned income from 2019 can be used to calculate the 2021 Earned Income Credit. The 2020 earned income, however, cannot be used.
"You may elect to use your 2019 earned income to figure your EIC if your 2019 earned income is more than your 2021 earned income. For details, see Pub. 596.
You can't use your 2020 earned income instead of your 2021 earned income. You can only use your 2019 earned income if it is more than your 2021 earned income."
To make this election, enter the 2019 earned income on screen EIC.