Between June 2011 and May 2012, more than 300,000 seniors and people with disabilities with Medi-Cal were moved from fee-for-service Medi-Cal into Medi-Cal Managed Care (as part of California’s “Bridge to Reform” Section 1115 demonstration project). Dr. Carrie Graham of HRA led a mixed-methods evaluation of this mandatory transition. The evaluation used focus groups and a telephone survey of beneficiaries to learn about beneficiaries’ experiences. The study was funded by the California Health Care Foundation and the California Department of Health Care Services (DHCS). An advisory group of diverse stakeholders provided input at all stages of the research. In a second, related study, HRA interviewed stakeholders to assess how the health system, including the state, health plans, providers, and community-based organizations responded to and were affected by the transition. This study was funded by the Kaiser Commission on Medicaid and the Uninsured. Methods The evaluation used both telephone survey and focus group methodologies. The telephone survey—conducted in English and Spanish—documented the experiences of 1,515 randomly selected Medi-Cal beneficiaries who transitioned to Medi-Cal managed care between June 2011 and May 2012. Survey staff received special training for conducting interviews with persons with disabilities. Persons using sign language could take the survey through video relay or instant messaging technology. Other accommodations, such as the use of proxies, or completion of the survey in installments, were available. Focus groups supplemented the telephone survey, allowing researchers to document the experiences of additional language groups, hard-to-reach populations, and small but medically vulnerable groups. The evaluation included focus groups with the population’s three largest language groups after English and Spanish. These were Armenian, Vietnamese, and Chinese. Additional focus groups documented the experiences of beneficiaries who were homeless or marginally housed, those on dialysis, and those with developmental disabilities. Key informant interviews and consultation with a stakeholder advisory group helped researchers document how this major change in service delivery impacted the health system.