What’s the difference between $20 and 20%? Unless you work in healthcare (and sometimes even then) you probably don’t know the difference between a co-payment and coinsurance. Or covered and non-covered services, and in- versus out-of-network providers, for that matter. If out-of-pocket limits sounds like Greek to you, I highly recommend a New York Times primer on the subject of basic US health insurance terms. It can help you make more informed decisions when choosing and using your health plan. Because 20% of $100,000 is significantly more than $20, wouldn’t you agree?