Reducing long-term cost by transforming primary care: evidence from Geisinger's medical home model.

Objectives: To estimate cost savings associated with ProvenHealth Navigator (PHN), which is an advanced model of patient-centered medical homes (PCMHs) developed by Geisinger Health System, and determine whether those savings increase over time.

Study Design: A retrospective claims data analysis of 43 primary care clinics that were converted into PHN sites between 2006 and 2010. The study population included Geisinger Health Plan's Medicare Advantage plan enrollees who were 65 years or older treated in these clinics (26,303 unique members).