The IRS has requested that you do Not file a 2020 amended tax return at this time for the exclusion.
See this IRS statement - https://www.irs.gov/newsroom/irs-statement-american-rescue-plan-act-of-2021
For those who received unemployment benefits last year and have already filed their 2020 tax return, the IRS emphasizes they should not file an amended return at this time, until the IRS issues additional guidance.
