Inclusion Criteria

1. ≥ 21 and ≤ 70 years of age

2. Moderate-to-severe obstructive sleep apnea (defined as apnea-hypopnea index of 15-50 events/hour on baseline screening polysomnogram)

3. Participant intolerant of positive airway pressure therapy (defined as < 2 hours of use per night for ≥ 5 nights per week)^*

4. Participant signs and dates a written informed consent form and indicates thorough understanding of the study protocol, procedures, and risks

^*Mask leaks, claustrophobia, discomfort, latex allergies, recurrent upper respiratory infection, noise disturbance, restricted movement limiting sleep

Exclusion Criteria

1. Any evidence that apnea is not caused by the base of the tongue (i.e. central apnea, neurologic disorder, retropalatal collapse, nasal obstruction)

2. Any condition likely requiring magnetic resonance imaging

3. Any factor that, in the surgeon’s judgment, would pose a risk to surgery or placement of a long-term implanted device

4. Any factor that, in the surgeon’s judgment, would make the participant unlikely to respond to Magnap treatment

5. Congenital anomalies of the larynx, pharynx, or trachea, or any other anatomical abnormality of the head, neck, or chest that would be a contraindication to placement of the Magnap device or external brace usage

6. No exclusion criteria based on gender, race, or ethnicity