Patient-centered medical homes in Louisiana had minimal impact on Medicaid population's use of acute care and costs.

The patient-centered medical home model of primary care has received considerable attention for its potential to improve outcomes and reduce health care costs. Yet little information exists about the model's ability to achieve these goals for Medicaid patients. We sought to evaluate the effect of patient-centered medical home certification of Louisiana primary care clinics on the quality and cost of care over time for a Medicaid population. We used a quasi-experimental pre-post design with a matched control group to assess the effect of medical home certification on outcomes. We found no impact on acute care use and modest support for reduced costs and primary care use among medical homes serving higher proportions of chronically ill patients. These findings provide preliminary results related to the ability of the patient-centered medical home model to improve outcomes for Medicaid beneficiaries. The findings support a case-mix-adjusted payment policy for medical homes going forward.