This is a five-year, single arm, multi-center trial to evaluate the long-term safety and efficacy of the Maestro Rechargeable System in treating obesity. The study will include an observational arm and a randomized sub-study.

The study evaluates the safety and efficacy of the vBloc Therapy delivered by the Maestro Rechargeable System for the treatment obesity. The Maestro Rechargeable System delivers intermittent, electrical blocking signals to the anterior and posterior trunks of the intra-abdominal vagus nerve (termed vBloc Therapy) and is designed to reduce sensations of hunger and produce satiety leading to weight loss.

Subjects in the observational arm (100 subjects total) will receive the device implant and use the vBloc Achieve Weight Management Program.

The randomized sub-study (100 subjects) will randomly assign subjects (1:1) to either treatment (50 subjects) or control (50 subjects). The treatment arm will receive the device implant and use of the vBloc Achieve Weight Management Program. The control arm will participate in the Control Weight Management (CWM) during a 6 month period prior to receiving the device implant and using the vBloc Achieve program.

The vBloc Achieve Weight Management Program consists of recommendations regarding diet, exercise and behavior modification, and will be utilized by all subjects following their device implant.

Inclusion Criteria:

1. Signed informed consent
2. Body mass index (BMI) ≥ 40 kg/m2 to 45 kg/m2 or BMI ≥ 35 kg/m2 to 39.9 kg/m2 with one or more obesity related co-morbid conditions
3. Females or males. Note: females of child-bearing potential must have a negative urine pregnancy test at Screen and also within 14 days of implant procedure followed by physician-approved contraceptive regimen for the duration of the study period.
4. At least 18 years of age
5. Failure to respond to supervised diet/exercise program(s) in which the subject was engaged within the last five years
6. Ability to complete all study visits and procedures

Exclusion Criteria:

1. Patients with cirrhosis of the liver, portal hypertension, or esophageal varices.
2. Patients with a large (>5cm) symptomatic hiatal hernia
3. Patients for whom magnetic resonance imaging (MRI) is planned
4. Patients at high risk for surgical complications
5. Patients who have a permanently implanted, electrical-powered medical device or gastrointestinal device or prosthesis (e.g. pacemakers, implanted defibrillators, neurostimulators)
6. Patients for whom shortwave, microwave, or therapeutic ultrasound diathermy is planned Note: Diathermy is any treatment that uses high-frequency electromagnetic radiation, electric currents, or ultrasonic waves to produce heat in body tissues. Patients absolutely CANNOT be treated with any type of shortwave, microwave, or therapeutic ultrasound diathermy device whether or not it is used to produce heat. These treatments should not be applied anywhere on the body.
7. Current medical condition that, in the opinion of the investigator, would make the subject unfit for surgery or that would be exacerbated by intentional weight loss. Some examples include diagnosis of cancer, recent heart attack, recent stroke or serious trauma.
8. Recent cessation of cigarette smoking (prior 2 months)
9. History of bariatric surgery, Nissen fundoplication, gastric resection, major upper-abdominal surgery, or other abdominal procedures at the discretion of the investigator (acceptable surgeries include cholecystectomy or hysterectomy)
10. Patients with recent (<2 years) or current history of illicit drug abuse
11. Patients with significant psychiatric disease including borderline personality disorder, psychosis, schizophrenia, unstable depression, suicidal ideation, or mental retardation