How long could it take?

 With BCBS IL it took me 3 days to get approved.

Insurance took under one week, and the surgeon's office offered me a time for 2 weeks later. I opted to have a date 3 months later because it worked better for me, but YMMV.

I have BCBS-Federal through hubby's insurance and it took me about a week to get approved and from seminar to approval about 5 months..only because I was dealing with hives for 3 of those months and was on steriods and shots twice....and they are coming back again today...so I'm proceeding with surgery.....hopefully they will go away after surgery.  

I first looked into WLS last october, and had to have six monthly nutrition appointments, bloodwork, psych eval, sleep study, upper endoscopy, more bloodwork, and then submitted it all to my insurance company (Tricare Reserve is for military reservists and their families) It was submitted on a monday and approved on wednesday and right away i scheduled surgery for about three weeks later. My actual surgery date was almost six months to the day from when i sat in on a group Q&A about WLS in my surgeons office. I had RNY gastric bypass on April 10th and spent 2 nights in the hospital. So far so good! I wish you the best of luck!!

I think it depends on how long the insurance approval actually takes and how booked your surgeon is.  I think three months might be in the ballpark in most instances.

I lucked out as my surgeon had a cancellation right at the time I was booking my surgery, so I was slipped into the slot.