The primary objectives of this study are 1) to evaluate the longer-term impact of an adjunctive, low-cost financial incentives intervention (relative to standard care) on smoking abstinence rates among socioeconomically disadvantaged individuals participating in a clinic-based smoking cessation program and 2) to identify treatment mechanisms and contextual factors associated with cessation outcomes among intervention participants using both traditional and ecological momentary assessment approaches. Those randomized to the financial incentives intervention will have the opportunity to earn small gift cards for biochemically-verified abstinence through 12 weeks post-quit. We hypothesize that individuals who are randomly assigned to the adjunctive CM intervention will have significantly higher rates of biochemically-verified abstinence at the 26-week post-quit follow-up than those assigned to Usual Care. In addition, we hypothesize that several factors related to socioeconomic disadvantage will be directly associated with non-abstinence, especially greater stress/adversity, limited psychosocial resources, greater negative affect, greater nicotine dependence, and poorer treatment adherence. The primary study endpoints will include self-reported tobacco use/abstinence, expired carbon monoxide (CO) levels (i.e., the amount of carbon monoxide present in an individual's breath when they breathe out), and saliva cotinine levels at 26 weeks post-quit attempt, though smoking status will be assessed at all visits. Traditional questionnaire measurement and ecological momentary assessment (EMA) will be utilized to measure potential treatment mechanisms including motivation, self-efficacy, and treatment adherence. Other variables including stress/adversity, psychosocial resources, negative affect, nicotine dependence, and treatment adherence will also be assessed.