If your e-file return status has not been accepted or rejected yet with e-file then you will need to wait for an update on the status of your return.
If your return was already accepted, then you will need to file an amended return to correct your filing status. If you had a refund with your original return with the incorrect filing status, you should typically wait until the refund has processed before you file an amendment. That allows you the opportunity to see if the IRS makes any adjustments to your return or sends you an inquiry about the return. However, if you will have to repay any of your refund, filing an amended return with the repayment before the tax deadline is a good idea so that you avoid any penalties for the difference in the amount due for 2020.
If you owed money with your original return and your return was already accepted, do your amended return so that you can ensure that your full taxes due with the change in filing status are paid on time.
If your e-file is rejected, then you will be able to go back into your return, make the change to your filing status and check your return for any other changes you might need to make, and then resubmit your e-file.
If you chose to paper file your return by mail, you will want to wait for the return to be processed by the IRS and then amend your return, keeping in mind that you want to make sure that any additional taxes that may be due with the change in filing status are paid by the tax deadline.
