Abstract
This article explores factors that facilitate or impede data sharing and linkage collaborations between state public health agencies and managed care organizations (MCOs). The exploration is based upon a review of both recent literature and the four years' experience of the Massachusetts Health Assessment Partnership (MHAP). MHAP has undertaken six collaborative data sharing and linkage projects that have involved diverse topics and methods. This article summarizes both exogenous and endogenous factors that have affected MHAP as a successful collaboration and indicates those factors that might be replicated in future collaborations between public health agencies and MCOs in other locations.