The messaging you describe is perfectly normal for the IRS. There's absolutely no reason to necessarily think that you're under review or that something is wrong with the processing of your tax return (absent clear information to the contrary) so please don't worry. The messages and bars on the IRS.gov's "Where's My Refund" webpage change all of the time; and sometimes the same message is displayed continuously. If it still says "processing" or "received" then that's actually a good thing. If your tax return ever is chosen for further review, or an actual audit (which is a somewhat rare event), then the website should indicate that, and also let you know to expect an IRS notice or letter by mail. You haven't observed any message like that, have you?
who do have their returns held for review, or who expect to receive an
IRS notice, tell us that such a message appears clearly on the Where's My Refund
website. The behavior that you observe is more
likely an indicator that your tax return is simply moving through the
processing system. It could also be that the IRS is checking for
additional information on something related to your tax return (like
matching your reported W-2 data with that separately reported to the IRS
by your employer); but we
wouldn't call that a review . . . perhaps only a small delay.
If enough time passes after filing (21 days after e-file, or 6 weeks after paper file), and there is no new information, at that time the IRS indicates that you can call them for additional information, using the phone number provided on their Where's My Refund website.
now, the best course of action is patience. The IRS doesn't always
move as fast as taxpayers would like (especially when waiting for a
refund). This year is especially slow, because the IRS is charged with
implementing several new tax laws and executive directives, including the 2015