Using a Sequential Multiple Assignment Randomized Trial (SMART) design, this project is a two-arm, two-stage randomized trial of 632 adult PWH who smoke cigarettes and receive care in one of three health systems. At inception, participants will be randomized to either combination nicotine replacement therapy (NRT, patch + short-acting NRT) or combination NRT+contingency management (CM). At 12 weeks, responders (non-smoking participants confirmed by exhaled carbon monoxide [eCO]) in both arms will receive 12 more weeks of the same treatment. Non-responders (participants with continued smoking by self-report and/or eCO) in both the NRT and NRT+CM arms will be re-randomized to 12 weeks of treatment, either with medication switch to varenicline (VAR) or intensified level of CM (start CM if no CM during first 12 weeks, or CM with higher reward schedule ["CM plus"] if NRT+CM group initially). The intervention will be delivered by trained clinical pharmacists. The primary outcome will be eCO-confirmed abstinence at 24 weeks post-enrollment. The specific aims of the proposed study are to: (1) identify the optimal adaptive approach to promote eCO-confirmed smoking abstinence (2) study the effectiveness of various adaptive strategies on CD4 count, HIV viral suppression, and VACS index (validated measure of morbidity and mortality risk); and (3) grounded in implementation science and using a Hybrid Effectiveness-Implementation Type I design, identify barriers and facilitators to delivering our intervention to inform future implementation.