The American health-care system occupies its own peculiar niche, because it’s a hodgepodge of all four models. According to the U.S. Census Bureau, in 2014, 55 percent of Americans had employer-sponsored health insurance, 37 percent were covered by some form of government health-care program, 15 percent paid for private insurance themselves, and 10.4 percent (or 33 million people) had no health insurance at all.

