The American healthcare system is complex. It was not created complex and expensive from its origins, but evolved to become this way over a period of about 100 years. There is nothing inherent in the way it evolved. It could have been different. But many decisions, often made for reasons having nothing to do with improving healthcare, shaped the healthcare system we have today. Explaining how it works and doesn’t work, its problems, attempts to reform it, and how recent reforms may transform it requires considering an unusual combination of topics.