Can I get gastric bypass covered by insurance or medicaid?

Usually. Gastric bypass is usually covered by most insurances including medicare and medicaid. There are often requirements such as doctor supervised weight loss for a number of months, or the surgery to be performed at a bariatric center of excellence. But yes it is covered usually.
Yes or No. Some insurance companies would decline because it is a cosmetic proceedure, unless you have diabetes, hypertension and life-threatening medical conditions. Medicaid , most surgeons accept this plan. I see obese patients refer to me by bariatric or plastic surgeons to lose 30 lbs. Before they do the operation.