Maine’s Medicaid program, called MaineCare, provides health care coverage to one in five state residents. Paul Saucier gives an overview of MaineCare’s services, eligibility categories, and financing. He discusses root causes of MaineCare’s continued expansion in breadth and cost, which has prompted reform proposals to rein in what many believe is unsustainable growth. Examining reform effort in other states, Saucier cautions that we need to learn from these experiments. Finally, he raises important questions for policymakers related to MaineCare’s mission, its complexity, and the stability of its financing. Two commentaries provide additional viewpoints on these questions. Lisa Pohlmann and Christine Hastedt critique reform efforts in several states and emphasize the key role of MaineCare in the state’s overall health care system. Dr. Erik Steele discusses MaineCare from the providers’ perspective. He suggests that delays and problems in the state’s reimbursement to providers have led to doubts about the state’s credibility both as a payer and as a health care systems change leader.