 This study is designed to evaluate the feasibility and provide preliminary evidence for efficacy of a 12-week contingency management intervention to promote weight loss in overweight and obese low income adults in a community-based clinic. The study has three primary goals: a to determine if the contingency management treatment can be effectively applied to a new application, weight loss; b to obtain preliminary evidence for contingency managements efficacy in promoting weight loss and improving treatment retention, diet quality, physical activity levels, and self efficacy; and c to identify barriers and challenges to implementing contingency management for weight loss among low income patients. 