BACKGROUND: Medicaid beneficiaries at high risk for diabetes can benefit from the Diabetes Prevention Program (DPP) lifestyle intervention. The We Can Prevent Diabetes (WCPD) trial examined whether financial incentives are more effective than no financial incentives in sustaining participation in the DPP and increasing weight loss. Here we describe the study design and baseline characteristics. METHODS: The WCPD was a 3-arm group-randomized controlled trial. Medicaid beneficiaries were aged 18 to 74years, had prediabetes or gestational diabetes, and were overweight or obese. Subjects enrolled from 13 primary care clinics into groups of 8 to 15 participants. Participants received the 12-month DPP delivered by the YMCA or trained clinic staff, free of costs. Participants from groups randomized into the intervention conditions were eligible to receive incentives up to $520 by attending sessions and meeting weight loss goals. RESULTS: The WCPD enrolled 1154 participants into 98 groups. Among the 847 attending at least one DPP session, 71.2% were women; the mean age was 48.3years; 79.3% were obese; and 87.6% entered the study with an elevated HbA1c or fasting plasma glucose. Participants' primary languages were Somali (21.0%), Hmong (3.1%), Spanish (2.2%), or English (72.4%). CONCLUSIONS: The WCPD trial demonstrated that a collaborative approach with primary care clinics and the YMCA can efficiently identify, enroll, and deliver the 12-month DPP to Medicaid beneficiaries. If the WCPD incentive arms increase attendance and weight loss, the use of financial incentives may be an avenue for engaging low-income, high-risk patients in lifestyle change.