I have Aetna through my wife's job, and while Aetna DOES cover it, I had a heck of a time getting approved, because at the last minute (3 weeks before surgery, after completing a 3-month program with all the bells and whistles), contrary to everything we'd been told, I get a call that Aetna has denied me because my wife's employer put an exclusion for weight-loss surgery in their plan. I was devastated and angry. But it turned out that there just was a wording difference between the plan the company actually had, and the plan that Aetna thought they had. Yes, there was, according to the company, a general exclusion, but it would be waved if you could prove "medical necessity". But Aetna didn't have that part in their records. So, we were told they'd fix the error, but it would take a couple of weeks (!!!???). Okay. So a couple of weeks later we re-submit, and now they say "Okay, so we DO cover this, but we need to see weight records from the past two years from your doctor." I'm like, WHAT. I hadn't seen a doctor that weighed me since 2006. I managed to get THAT record, and praise the Lord they took it as fulfilling the requirement.
I got official approval literally on the Friday before my scheduled Tuesday surgery. Which was, I was THEN told, too close, because the hospital needed me to come in for pre-admission testing first. Did that, and now my surgery is set for this coming Tuesday.
So, long story short, yes, Aetna covers it, but make sure you know all the details.