In October 2008, the Blue Cross Blue Shield of Massachusetts (BCBSMA) Foundation launched the Closing the Gap on Health Care Disparities Initiative that supported 11 community-based coalitions across Massachusetts in addressing disparities in health care and outcomes. The projects selected a variety of health problems (e.g., diabetes, obesity, HIV/AIDS, and adolescent pregnancy) that differentially affect people with various demographic characteristics (e.g. race, ethnicity, economic status, and sexual orientation). Grantees received one-year planning awards to develop their ideas, assess needs, hone their approaches, and strengthen their coalitions. They then received two-year implementation grants. The Foundation also established a learning com- munity where grantees shared their experiences and gained a stronger understanding of suc- cessful techniques for reducing health disparities. This report summarizes findings and important lessons from the Initiative that may be helpful to foundations, community organizations, and health care institutions working on similar projects.