This Visualizing Health Policy infographic examines unexpected and “surprise” medical bills in the United States. Out-of-network charges typically expose patients to higher cost-sharing when they use services and may lead to balance billing—in which health care providers bill patients directly, often at an unexpectedly higher rate. In the past 2 years, 1 in 5 insured adults had an unexpected medical bill from an out-of-network provider. Overall, two-thirds of adults are worried about affording unexpected medical bills for themselves and their family. In emergency departments across the country, 18% of visits result in at least 1 surprise bill, but rates vary by state. Politically, majorities of Democrats and Republicans support government action to protect patients against these surprise bills.