The IRS estimates that most refunds will be sent within 3
weeks after your e-filed returns are accepted. Many refunds will come sooner.
There's no way of knowing exactly when the IRS will update to refund sent. You
will need to keep checking the Where’s
My Federal Refund? tool for updates.
Updates are made daily, usually overnight.
https://ttlc.intuit.com/replies/3332479
If your return was accepted 21 days ago or more, you
can follow the instructions in the following FAQ to contact the IRS for further
assistance.
https://ttlc.intuit.com/replies/3302084