The use of incentives to promote healthy behaviors in the Medicaid population is understudied. The We Can Prevent Diabetes study is designed to assess the effect of financial incentives on attendance and weight loss among Medicaid beneficiaries participating in the group-based Diabetes Prevention Program (DPP). We conducted a pragmatic 3-arm cluster-randomized study of individually earned (IND) and individual plus group earned (GRP) financial incentives against an attention control (AC) among DPP participants. Medicaid beneficiaries with prediabetes (HbA1c 5.7-6.4%; FPG 100-125 mg/dL) or history of gestational diabetes, and a BMI = 25 kg/m2 (= 23 kg/m2 for Asians) were enrolled into the DPP (6-15 participants/class) that was delivered by certified DPP coaches. During 16 weekly Core sessions, participants received incentives for weekly attendance and for achieving at least 5%, 7% and 10% weight loss. A total of $315 in incentives could be earned by participants in the IND or GRP arms. We analyzed differences in weight loss and attendance across the three study arms using hierarchical models to accommodate randomization at the class level and repeated time measures. There were 93 DPP class cohorts; 849 participants attended at least one session. Mean age and BMI were 48.3 years and 36.5 kg/m2; 81% were non-white or Hispanic, and 28% reported English was not their primary language. During the core sessions, attendance declined 38% (IND), 41% (GRP), and 63% (AC), p<0.01. Weight declined 2.1% (IND), 2.3% (GRP), 2.3% (AC), p=0.60. Participants achieving at least 5% weight loss were: 5.9% (IND), 9.4% (GRP), and 7.1% (AC), p=0.24. In this culturally diverse Medicaid population, relative to the attention control, financial incentives increased participation in the DPP but did not increase weight loss during the core sessions. Further research is needed to understand the factors that facilitate or limit healthy behaviors in this population.