The American Rescue Plan Act of 2021, signed into law on March 11, includes a third round of stimulus payments. The IRS will begin depositing payments into accounts immediately, with the first wave of direct deposits hitting accounts early next week.
I understand the IRS will use direct deposit (DD) information from 2020 and 2019 tax returns, with 2020 taking precedent if available. If DD info is not present on tax returns, the IRS will likely use DD info entered by the taxpayer into the Get My Payment tool. If no DD info is available, the taxpayer will receive a check or debit card.
The Get My Payment tool will not be updated with EIP3 data before Monday, March 15. I don't believe the IRS will be collecting any additional DD info through the GMP tool for EIP3.
Payments received in this third round of stimulus do not impact 2020 tax returns.
For more information, look for an IRS Press Release later today:
https://www.irs.gov/newsroom/news-releases-for-current-month