Final answer:
The United States was the only high-income country without universal health coverage until the implementation of the Affordable Care Act. The U.S. health care system is primarily run by private firms, with a mix of not-for-profit and for-profit entities and government programs like Medicare and Medicaid supplementing insurance for certain groups.
Step-by-step explanation:
Until recently, the United States was the only high-income nation without some form of universal health coverage for all citizens. The U.S. health care system is unique in that private firms pay and provide for most health insurance. By contrast, many other countries offer national medical insurance and various social welfare benefits.
The Patient Protection and Affordable Care Act (PPACA or 'Obamacare') attempted to address this by mandating that all Americans purchase health insurance and preventing providers from denying coverage based on preexisting conditions.
In an international context, the United States healthcare industry includes a mix of not-for-profit and for-profit enterprises, with the government providing health insurance for the elderly through Medicare and for the poor through Medicaid.
Despite these programs, millions of Americans remained uninsured. Discussions about socialization of medicine and various care options have been ongoing, as the ACA itself has faced legal and political challenges.