I have Anthem Blue Cross Blue Shield of California and my timeline looks like this

August 12th - Info Session
August 21st - Lab work
August 26th - Psychological Screen
August 28th - Psychological Eval
August 30th - Sleep Study
September 5th - Dietician Appointment
September 16th - APPROVAL!!! HORRAY

I called my insurance company and was told by customer no service that my policy did not cover bariatrics, but once my doctors office called they found out that was incorrect. They were able to get a clear concise list of requirements and as you can see the approval took less than two weeks. I wish you the best success.