Providing smoking cessation treatment in conjunction with the recently expanded lung cancer screening guidelines is estimated to substantially reduce lung cancer deaths and increase life-years gained compared to conducting lung screening alone. Although CMS recommends that individuals undergoing lung screening who currently smoke are offered cessation treatment, there are multiple barriers to treatment delivery. Improving the evidence-base of cessation treatment for patients undergoing lung screening and methods to promote the systematic uptake of cessation treatment into routine practice, particularly among diverse populations, is essential for realizing the maximum benefit of lung screening. Guided by the Practical, Robust, Implementation & Sustainability framework, we will extend our prior work (CA R01207228). We propose a health system-level, pragmatic, randomized trial to compare the effectiveness of two evidence-based cessation treatments, with implementation strategies designed to address barriers to reach and engagement, particularly among underserved groups (e.g., racial and ethnic minority groups, underinsured patients, and patients not ready to quit) who are less likely to receive cessation treatment. To maximize generalizability to other health systems and to improve reach among heterogeneous groups, all patients scheduled at one of the 10 lung screening sites at MedStar Health, the largest and most diverse health system in the Mid-Atlantic, will be identified via the EHR, contacted for enrollment using an opt-out approach, and randomized to: 1) Quitline E-referral (QL-E; N=594) via the EHR and quitline integrated system, including proactive outreach and standard phone-based counseling+ nicotine replacement provided by the quitline vs. 2) MedStar Health System (MHS; N=594), a centralized, phone-based+ NRT intervention adapted and improved from our prior trial, with a randomized stepped care intervention for those who are not abstinent at 3 months. Specific aims are: 1. To compare e-referral to the Quitline vs. the centralized Health System intervention. Primary outcomes are: bioverified abstinence from cigarettes at 3- and 6-months. We will assess intervention mediators (e.g., treatment engagement) and moderators (e.g., readiness to quit) at 6-months. 2. To evaluate reach and engagement overall and by subgroup (e.g., race and ethnicity, underinsured, readiness to quit) and using mixed-methods to understand the contextual factors related to the feasibility and acceptability of the interventions and implementation strategies. 3. To conduct an economic analysis to evaluate costs, average and incremental cost per quit, and budget impact of the intervention at 3- and 6-months from the health system perspective. Proposal strengths include testing the effectiveness and economic outcomes of two cessation interventions while simultaneously laying the groundwork for future implementation within this and other diverse health systems. Our innovative approach capitalizes on the EHR for recruitment, provides multilevel training focused on diverse populations, and accounts for intervention context to inform future care delivery.