With single-payer public health insurance again on the political radar in the United States at both the state (California) and federal (Democrat party) levels, the performance of the Canadian health care system during the last 50 years and the lessons it may offer should be considered. Canadians are proud of their universal approach to health insurance based on need rather than income. The system has many strengths, such as the ease of obtaining care, relatively low costs, and low administrative costs, with effectiveness and safety roughly on par with other countries, including those, such as the United States, that spend considerably more per capita. There are increasing frustrations, however, with system performance, especially with issues related to access and coordination of care. Medicine has changed dramatically since the introduction of Canadian Medicare in the late 1960s, which primarily covered acute care physician and hospital services-the needs of the time. Meaningful reforms that match coverage and services to changing needs, especially those of community-based patients with multiple chronic conditions, have been difficult to implement. The status quo represents a compromise struck decades ago between payers and physicians and organizations that provide health care, and the current system works just well enough for those who both need it and vote. Enacting substantial change simply carries too much risk. Perhaps the most important lesson that the United States can learn from Canada's experience during the last 50 years is that a single-payer health care system solves a lot of problems, but it does not equate to an integrated, well-managed system that can readily meet the changing health care needs of a population.