RecruitingBehavioural interventionSmoking Cessation CM for Veterans With or at Risk for CancerTobacco use among US Veterans poses significant health problems and challenges to their overall well-being. The aim of this project is to evaluate the effectiveness of a program called Contingency Management (CM) in helping Veterans quit smoking during lung cancer screening or cancer care at VA clinics. CM is a behavioral treatment that uses rewards to encourage smoking cessation when verified through biological testing. In the first year, the researchers will develop a mobile CM protocol based on feedback from Veterans and healthcare staff through focus groups. In the second year, they will conduct a pilot study to test the feasibility of the mobile CM program along with counseling and medication for 20 Veterans over a five-week period. The success of the pilot study will determine whether to proceed with a larger randomized controlled trial (RCT) in years three to six, comparing the efficacy of mobile CM with standard treatment. The project will take place at SFVA.