I’ve yet to receive my tax refund from my 2020 return that I filed in March of 2021. Can I sue the IRS?

Because IRS employees worked remotely due to the pandemic, the IRS still has a significant backlog of unprocessed income tax returns. There is no authority for an individual to sue the IRS for failing to timely remit a tax refund. However, the IRS must pay interest on the refund when it is finally sent. Interest accrues starting from 45 days after May 17, 2021, the filing deadline for the 2020 return, even though the return was filed prior to this date.