As of March 6, 2021, do we have to file amended tax return on the 10200 unemployment exemption? Also do we need to amend states too?

Hi there, as of March 6, 2021, will we need to file an amended federal tax return if the 10200 dollar unemployment exemption becomes law? Or maybe the IRS could automatically calculate the amount on our behalf and issue us a refund? 

Also, if we are required to file an amended federal return, will the 10200 unemployment exemption affect my AGI? Will it also affect my state taxes, in turn forcing me to amend my state tax return too?