Universal health care systems vary according to the extent of government involvement in providing care and/or health insurance. In some countries, such as the UK, Spain, Italy and the Nordic countries, the government has a high degree of involvement in the commissioning or delivery of health care services and access is based on residence rights not on the purchase of insurance. Others have a much more pluralistic delivery system based on obligatory health with contributory insurance rates related to salaries or income, and usually funded by employers and beneficiaries jointly. Sometimes the health funds are derived from a mixture of insurance premiums, salary related mandatory contributions by employees and/or employers to regulated sickness funds, and by government taxes. These insurance based systems tend to reimburse private or public medical providers, often at heavily regulated rates, through mutual or publicly owned medical insurers. A few countries such as the Netherlands and Switzerland operate via privately owned but heavily regulated private insurers that are not allowed to make a profit from the mandatory element of insurance but can profit by selling supplemental insurance.

Universal health care is a broad concept that has been implemented in several ways. The common denominator for all such programs is some form of government action aimed at extending access to health care as widely as possible and setting minimum standards. Most implement universal health care through legislation, regulation and taxation. Legislation and regulation direct what care must be provided, to whom, and on what basis. Usually some costs are borne by the patient at the time of consumption but the bulk of costs come from a combination of compulsory insurance and tax revenues. Some programs are paid for entirely out of tax revenues. In others tax revenues are used either to fund insurance for the very poor or for those needing long term chronic care. The UK government's National Audit Office in 2003 published an international comparison of ten different health care systems in ten developed countries, nine universal systems against one non-universal system (the U.S.), and their relative costs and key health outcomes.^[3] A wider international comparison of 16 countries, each with universal health care, was published by the World Health Organization in 2004 ^[4] In some cases, government involvement also includes directly managing the health care system, but many countries use mixed public-private systems to deliver universal health care.