Hypoglossal nerve neurostimulation implant is a surgically implanted device that stimulates protrusor branches of the hypoglossal nerve to effect upper airway opening during sleep. It has emerged as a treatment for patients with moderate-to-severe obstructive sleep apnea (OSA) who are intolerant to continuous positive airway pressure therapy. This chapter reviews the current evidence on indications, procedure, safety, efficacy, and outcomes associated with HGNS implant in the treatment of OSA.