NEW YORK (MainStreet) — Medical costs may not be going down, but they appear to be causing less stress on Americans' pocketbooks.

A new survey shows the percentage of persons under age 65 who were in families having problems paying medical bills decreased from 21.7% — or 57.6 million people — in the first six months of 2011 to 19.8% in the first six months of 2013 — or 52.8 million people. The percentage of children — those under 18 years of age — who were in families having problems paying medical bills also decreased — from 23.7% in the first six months of 2011 to 21.3% in the first six months of 2013.

The numbers come from a survey by the Centers for Disease Control and Prevention's National Center for Healthcare Statistics. The study defined medical bills as expenses from doctors, dentists, hospitals, therapists, medications, equipment, nursing homes and home care. Not surprisingly, the report found in the first six months of 2013, among people under the age of 65 and having problems paying medical bills, 34.3% were uninsured, 24.7% had public coverage, and 14.1% had private coverage. Also, in that same time period, 28.6% of poor, 33.3% of near poor and 14.3% of not poor persons were in families having problems paying medical bills.

While the numbers of those struggling with the high costs of medical care are falling, and the Affordable Care Act has brought private healthcare to millions, experts point to the numbers still showing nearly one in five people struggling with their bills and the cost of care.

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"In 2013, over 20% of American adults are struggling to pay their medical bills, and three in five bankruptcies will be due to medical bills," said Christina LaMontagne, vice president of health for the personal finance website NerdWallet.

Nerdwallet's own recent study was strikingly similar to the NHIS's. It estimates in 2013, 56 million Americans under age 65 will have trouble paying medical bills and more than 35 million American adults between the ages of ages 19 and 64 — will be contacted by collections agencies because of unpaid medical bills.

"Furthermore, 25 million people hesitate to take their medications in order to control their medical costs," LaMontagne said. "Unfortunately this can lead to even worse financial outcomes as preventative treatments are not rendered and patients end up using expensive ambulance and ER care as their health worsens."

The report also said nearly 17 million American adults will receive a lower credit ratings due to high medical bills and more than 15 million will use up all their savings to pay medical bills. More than 11 million adults are expected to use credit card debt to pay off their bills and nearly another 10 million will be unable to pay for basic necessities like rent and food because of their bills.

LaMontagne also doesn't see the federal government's universal health insurance mandate as a panacea.

"Insurance is no silver bullet," LaMontagne said. "Even with insurance coverage, we expect 10 million Americans will face bills they are unable to pay."

Also See: Obamacare Saved My Life and My House

For those that cannot pay, bankruptcy will be an often used option, and 1.7 million Americans live in households that are expected to declare bankruptcy due to their inability to pay medical bills, with three states — California, Illinois and Florida — expecting to account for more than a quarter of those living in medical bill-related bankruptcy.

--Written by Chris Metinko for MainStreet