Let’s say that a patient schedules surgery for a knee replacement. The patient makes sure that both the surgeon and the hospital are in-network. But little does he know that the anesthesiologist isn’t. A few weeks later, he is hit with a medical bill for anesthesia at a surprisingly high out-of-network rate.

This unfortunate situation is just one of many examples of surprise billing. And it could become more problematic with the rising number of narrow networks that insurers are offering on Obamacare’s Exchanges.

Almost half of ACA plans feature both small and extra small hospital networks.  Small networks cover less than 70 percent of local hospitals, while extra small networks give policyholders access to fewer than 30 percent of local hospitals.

Read more here in my latest newsletter about narrow networks, how states are responding to surprise billing, and how cash-based surgery gets rid of the issue.