Medicare covers the following:
- BPD/DS aka DS (Biliopancreatic Diversion with Duodenal Switch) (lap and open)
- RNY (Roux-en-Y Gastric Bypass) (lap and open)
- AGB aka Lap-Band (Adjustable Gastric Banding) (lap only)
Each procedure must be performed in Medicare-approved (as in Center of Excellence) facilities. For a listing of them, click on this link:
http://www.cms.hhs.gov/MedicareApprovedFacilitie/BSF/list.asp#TopOfPage
Medicare does not cover the following:
- VSG (Vertical Sleeve Gastrectomy) (lap and open)
- VBG (Vertical Gastric Banding)
- AGB aka Lap-Band (Adjustable Gastric Banding) (open only)
- Gastric Balloon
- Intestinal Bypass
As for revisions, Medicare covers open and laparoscopic Roux-en-Y gastric bypass (RYGBP), laparoscopic adjustable gastric banding (LAGB) and open and laparoscopic biliopancreatic diversion with duodenal switch (BPD/DS) if certain criteria are met and the procedure is performed in an approved facility.
Source: http://www.cms.hhs.gov/mcd/viewncd.asp?ncd_id=100.1&ncd_version=2&basket=ncd%3A100%2E1%3A2%3ABariatric+Surgery+for+Treatment+of+Morbid+Obesity
Medicare does not pre-authorize any medical services that are considered "medically necessary". For WLS, "medical necessity" is defined as follows:
BMI of 40 WITHOUT any co-morbidities
BMI of 35 WITH at least one serious co-morbidity (such as hypertension [high blood pressure], heart disease, diabetes (Type 2), and sleep apnea)
Hope this helps!