New York (MainStreet) - America has reached a tipping point when it comes to medical debt. According to the Consumer Financial Protection Board, these bills now account for more than half of all collections reported on consumer credit scores. Yet it’s an even bigger problem than most Americans realize, because getting health insurance doesn’t always solve the problem.

In fact, it usually doesn’t. Some 70% percent of people who struggle to pay their medical bills are insured.

A new Kaiser Family Foundation study takes a look at this problem. The reality of medical debt is that it often strikes out of the blue. People who end up dodging calls from a hospital’s debt collectors are frequently those with no other history of credit problems, according to study author Karen Pollitz. They often enjoyed financial security until illness or accident occurred, leaving them not only deeply in debt but less likely to seek future care for fear of running up even more impossible medical bills.

“For many people medical expenses are unexpected,” Pollitz said. “That’s why we have medical insurance, for ‘I didn’t know I was going to fall off my bike today and break my neck.’”

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That’s when co-pays can begin to mount, adding to a stack of medical bills that cancer patients can’t help but incur.

“Cost sharing levels under many health plans now exceed the resources that most families have on hand,” Pollitz’s study found. “In its most recent report on the economic well-being of U.S. households, the Federal Reserve found that only 48% of Americans would be able to completely cover a hypothetical emergency expense costing $400 without selling something or borrowing money.”

Under the vast majority of health plans today, even considering the ACA, cost sharing can easily exceed $400 even for relatively simple procedures. In 2014 the average workplace insurance plan had a $1,200 deductible (the amount an individual has to pay before insurance begins covering the rest). Affordable Care Act exchange plans can demand even more. Silver plans in 2014, by far the most popular option, had an average deductible of $2,563 for combined medical and prescription drug deductibles.

People trying to save money by purchasing a bronze plan paid a $5,300 deductible. Finally, co-pays and coinsurance can add even more to a patient’s out of pocket expenses, quickly running someone’s annual bills up to the new cap of $6,350 per person per year.

“The premium is the predictable cost that you know you’re going to pay whether you get sick or not,” she said. “So that gets a lot of focus, [and] there’s been a steady drift in terms of cost sharing upwards as insurers and employers have endeavored to keep cost sharing low.”

As a result, consumers chase premiums downward. Someone who isn’t already sick often will choose the lowest cost plan available, opting for the savings they know instead of the savings they might reap down the road. This makes sense, Pollitz said, right up until you run your bike into a tree and start having to shell out for deductibles and co-pays.

Although the ACA has now capped annual charges so patients no longer have the nightmare of five- or even six-figure bills they could never imagine paying, the reality for most people is that $6,300 is still an enormous sum of money. Most Americans simply don’t have that sitting around, and health problems aren’t something they can plan and save for like a new car.

The result is what Pollitz called an “invisible problem.” Most people think that the health care crisis is about opening up access to insurance, but that’s often just the first step. Medical care can be cripplingly expensive even with health insurance, and once the snowball effect starts, it can be difficult to stop. Worse, in an effort to do so, many people begin skipping needed treatments for problems that aren’t quite life threatening. Staring at a stack of chemotherapy bills, Pollitz said, some patients will simply skip their root canal and live with the pain.

“Under the ACA all private health plans have to have a limit," Pollitz said. "That limit, though, is pretty high. This year its $6,600 for a person, twice that if you have a family policy, and most Americans don’t have that much money lying around. So that gets into the ‘how can you have insurance and also get faced with medical bills that you can’t pay?’ [Having health insurance] is a huge improvement over being uninsured, but it’s not quite crossing the finish line.”

It all adds up to what is becoming the early legacy of the 21st century: debt from which the average American simply cannot escape.

--Written for MainStreet by Eric Reed, a freelance journalist who writes frequently on the subjects of career and travel. You can read more of his work at his website A Wandering Lawyer.