This preliminary study investigates hypoglossal nerve stimulator (HNS) amplitude changes and usage patterns during the initial HNS uptitration period to characterize when patients achieve their therapeutic amplitude. HNS therapy amplitudes, duration, and pause times were examined across the first 4 months of implant use. Average HNS therapy amplitude increased monthly from baseline (0.7 ± 0.3 V) to the first (1.1 ± 0.3 V), second (1.4 ± 0.4 V), third (1.7 ± 0.5 V), and fourth months (1.8 ± 0.5 V) (P < .001). After 4 months, 60% had reached a therapeutic amplitude. Average therapeutic amplitude was greater for patients who did not achieve therapeutic amplitude by month 4 than for those who did (2.6 vs1.6 V; P < .05). Body mass index, baseline apnea-hypopnea index, respiratory disturbance index, and initial HNS amplitude did not differ between the 2 groups. Predictors for therapeutic amplitude and other usage patterns requirefurther investigation.