Five percent of Medicaid patients account for 50% of total costs. Preventable costs are often incurred by patients with complex medical, behavioral, and social needs who disproportionately utilize acute care services. Evidence for design, implementation, and evaluation of complex care programs in the urban Medicaid population is lacking. The article provides a description of a complex care program (CCP), challenges, and early outcomes based on a pre-post evaluation. The CCP was located within an existing urban medical home. Patients were eligible if they lived within 10 miles of the clinic and had at least 2 inpatient visits and/or 3 emergency room visits within the prior 6 months. Ambulatory Care Groups® were used to predict estimated total costs of patients, who were included if potential cost savings exceeded $5000. Patient experience and quality of care were assessed using validated measures and costs. Return on investment was calculated based on investment and cost savings. Costs include visits (clinic, specialty, and emergency room), hospital admissions, medications, tests and services, as well as salary and benefits of clinical staff. Eighty-six of 211 eligible patients (41%) were enrolled during the first 18 months of the pilot program. There were positive trends in quality metrics and patient satisfaction. The pre-post evaluation demonstrated a reduction in emergency room visits and hospitalizations (67% and 65%, respectively), which resulted in a 2.2:1 return on investment. This article offers lessons learned to colleagues considering population health approaches in the care of high-risk Medicaid patients.