Under the Affordable Care Act, health insurance plans must offer emergency coverage, including Emergency Room visits and emergency transportation (ambulances, etc.). ER visits are commonly subject to a copay, but it is important to refer to the plan's Summary of Benefits and Coverage to confirm the coverage for that service.
What if an ambulance takes someone to an out-of-network hospital?
If there is an emergency situation where emergency transport is required and the nearest hospital is considered out-of-network, the insurance carrier will still treat services rendered there as in-network.
What about traveling outside of the USA?
All US health plans also cover emergency services overseas as though they were in-network. The situation must be serious, if not life-threatening, so going to the ER for, say, a sinus infection will not be covered. For more comprehensive benefits, it's recommended to look into dedicated Travel Insurance.