I’ve already filed my 2020 state and federal returns and the new stimulus bill will forgive $10,200 in unemployment benefits. This will significantly lower my taxable income. What do I do now?

[ee-ea]

WAIT!  Wait  for the taxing authorities to issue instructions.

[fanfare]

assuming it stays in all the way to the end,

that's a 2021 tax break for your 2021 tax return.

[vu8]

That would be lovely and clean! No need to file messy 2020 amended returns. Win Win for both IRS and tax filers. 

[jhatchdaniels]

This according to CNBC yesterday:

As part of that compromise, Democrats added language to the bill that would provide a tax waiver on up to $10,200 of unemployment insurance benefits for 2020, staff for Sen. Ron Wyden, D-Ore., confirmed Friday to CNBC Make It.