A medical device system and method are disclosed for treating obstructive sleep apnea. The system includes a pulse generator and a medical electrical lead including multiple electrodes carried by a distal portion of an elongated lead body. The method includes advancing the distal portion within protrusor muscle tissue below the oral cavity and delivering electrical stimulation pulses via the electrodes to sustain a protruded state throughout a delivery time period to sustain a protruded state of a patient's tongue throughout the therapy delivery time period. The therapy delivery time period may span multiple respiration cycles.
