A main responsibility of the HPC is to examine significant changes in the health care marketplace and their potential impact on cost, quality, and market competitiveness. This includes (1) implementing a first-in-the-nation registration program to provide transparency on the composition and function of provider organizations in Massachusetts (RPO), (2) tracking and analyzing the number, type, and frequency of material changes to the governance or operations of health care providers (MCNs), (3) evaluating the impact of significant provider transactions on the competitive market and on the state’s ability to meet the health care cost growth benchmark (CMIRs), and (4) collaborating with other HPC teams to catalyze improvements in the performance of the health care market, such as by analyzing the impact of market structure on cost trends and evaluating different approaches and identifying best practices for incenting provider performance.