Abstract: A non-invasive, removable intraoral electrical Stimulator or Pacemaker system and method is described, for electrically-stimulating and re-establishing the tone in the upper pharyngeal dilator muscle, the genioglossus and base-of-tongue muscles, for the treatment of Obstructive Sleep Apnea (OSA) in human adults and young adults. The Stimulator system consists of an intraoral Stimulator device assembly with a rechargeable battery, an external (inductive) Recharger appliance and an external hand-held (inductive) Programmer appliance. The Stimulator device assembly is inserted into the mouth by the OSA patient before sleep time and is removed when awake or during normal activity and placed in the charging cradle of the Recharger appliance for recharging the device battery. The physician uses the hand-held Programmer appliance to determine and set the patient-specific stimulation therapy parameters in the device, at the patient's initial evaluation.