This is true but complex. It depends on the type of service you receive. As a general rule, you'll need to pay a yearly deductible before receiving insurance benefits for non preventative care. This can be anywhere from $500 to $8000. High deductible plans are commonly referred to as "catastrophic" plans, because the deductible is so high, and the kind of people who purchase them are typically not wealthy, that their owners would only seek care in a true emergency where the service would exceed the cost of the deductible. After paying your deductible you will often also have a "co-pay" which is typically a flat rate based on the type of service. Something in the realm of $25 to $500. After that, many plans have something called "co-insurance" which is a percentage of the bill you are responsible for even if you have met your deductible. Say, 20%.

Add all these charges and fees up, you'll keep paying them until you hit your "maximum out of pocket." So as an example, I was hospitalized a few years back in December while on what would be considered a "good" healthcare plan. I paid my $1000 deductible, a $250 co-pay for emergency room care, and co-insurance of several hundred dollars. I stayed a single night in the hospital and received a CT scan. I was given Tylenol, released the next day, and referred to a specialist. I wound up seeing the specialist in January, so my deductible reset. I was given another CT scan, so I had to pay my $1000 deductible again. The total bill for the entire process pre-insurance was in the realm of $80,000. After insurance, I paid $5000, which was my entire life savings at the time. I didn't hit my maximum out of pocket for either year, so I got lucky in a way. I could have had to pay double what I did.