I received a CP63 and found this forum while trying to figure out how long it would take to get everything straightened out. I figured I would share my experience for anyone who got the same letter.
I filed 1/28 and was accepted same day. I’m a single mom and HoH so I have EITC and CTC. I received the PATH message on or about 2/9. It switched to processing on 2./18 with no bars and stayed that way until overnight last night.
On 2/22 I received a CP63 letter which was weirdly dated 2/29. I hadn’t filed in 2011 because I was on unemployment and didn’t owe taxes but the IRS wanted a 1040 for that year in order to release this year’s return. I downloaded my unemployment form from my state for 2011 and filled out a 2011 1040 online for free. I sent it out the next morning via regular mail and the IRS received it on 3/3.
I checked my return and account transcript yesterday and the CP63 hold was released and I got an 846 on my account transcript with a date of 03-27-2017. I checked WMR today and it says “Refund Approved” and to expect my refund in to my account by 3/15.
I’ll update if anything changes but it only took about 3 weeks in all for the the IRS to process my missing return and release refund.