Most OECD countries have achieved near-universal coverage of health care costs for a core set of services, which usually include consultations with doctors and specialists, tests and examinations, and surgical and therapeutic procedures (). Two OECD countries do not have universal health coverage. In Mexico, the Seguro Popular voluntary health insurance scheme was introduced in 2004 to provide coverage for the poor and uninsured, and grew so rapidly that by 2011, nearly 90% of the population was covered. In the United States, coverage is provided mainly through private health insurance, and 53% of the population had this for their basic coverage in 2011. Publicly financed coverage insured 32% of the population (the elderly, people with low income or with disabilities), leaving 15% of the population without health coverage.