Objectives: In this study, we assessed changes in dependence as smokers transitioned from cigarette smoking to exclusive use of the JUUL System ("JUUL"), contrasting users of 5.0% versus 3.0% nicotine concentration pods. Methods: Overall, 5246 adult (age ≥ 21) established smokers (> 100 cigarettes lifetime) who purchased a JUUL device completed online surveys at baseline, when smoking, and one and 3 months later; 1758 reported no past-30-day smoking ('switching') at one or both timepoints. Analyses compared dependence on cigarettes (at baseline) and JUUL (at follow-up), as assessed by the 4-item PROMIS scale (Range: 0-4). Results: Switching increased from Month 1 (18.3%) to Month 3 (28.6%); switchers at one month (Difference = 0.23) and 3 months (0.24) showed lower mean baseline cigarette dependence. Dependence decreased significantly (ps < .001) from baseline cigarette dependence to JUUL dependence at both one (from 1.82 to 1.59) and 3 months (1.97 to 1.73); changes did not significantly differ between users of 5.0% and 3.0% (ps > .43). Dependence on JUUL did not change significantly from Month 1 to Month 3. Conclusions: Dependence decreased as smokers transitioned from smoking to exclusive use of JUUL, similarly for users of both nicotine concentrations. Smokers who switch to JUUL may reduce their nicotine dependence.