For 2021 taxes, can I use may 2019 earned income, if I didn't file my 2019 taxes?

[ZoltanB45]

You will have to file a 2019 tax return for the activity in 2019. You absolutely cannot use the income from a prior year to prepare the current year's tax return.

Here is a link to the 2019 software if that is route you choose to go. 2019 Turbo Tax

[turgerel]

I wanted to clarify that it is I regards to the Earned Income Tax Credit. 

[KrisD15]

It is TRUE that taxpayers may be able to us their 2019 earned income for the 2021 Earned Income Credit, but you would need to have filed a 2019 return to establish a 2019 income that the IRS would agree with. You can still file a 2019 return, but it would take some time for the IRS to process that. 

According to the IRS:

"You can elect to use your 2019 earned income to figure your 2021 earned income credit (EIC) if your 2019 earned income is more than your 2021 earned income."