It is official that the IRS filing deadline has been extended from April 15th to May 17th. This extension is automatic so no form will need to be filed with IRS. Mississippi (and most other states) have also extended the deadline until May 17th.
Strangely, however, IRS did not extend the deadline for 2021 estimated tax payment due on April 15th. Honestly, this is just a stubborn and ignorant stance by the IRS commissioner. We will see if this deadline gets extended also, but for now the answer is no.
The AICPA is still pushing for the deadline to be extended until June. Stay tuned.