As a GENERAL rule (that is, it can vary), after your return is accepted, your direct deposit refund will appear in 2 to 3 weeks (obviously a function of how busy they are). If they issue your a refund check, I would bet on it taking up to two weeks on top of that.

If there are any questions on your return, then in the 3 to 5 week timeframe, you will often receive a letter from the IRS asking for additional information (respond to this quickly because they will usually hold up your refund until you have responded).