With more Australians travelling and working in the United States some visitors are learning the hard way that America’s health system can be a wealth hazard.

One Australian living in Hollywood had to pay $US20,000 (A$25,500) in healthcare bills for her family in 2017, despite having comprehensive health insurance.

Gwen John, who moved to Hollywood from Sydney four years ago, pays $US240 ($305) per month for her family’s health insurance – an amount subsidised by her husband’s employer – but last year had to pay extra for health care that wasn’t covered by insurance.

“They just charge so much more over here,” Ms John says. “I’m wondering whether these health insurance companies are making too much money, and it’s not about the best thing for the patient, or making sure everyone in America has access to health insurance.”

In the US there is no universal public healthcare system, only the elderly, disabled, poor, and very young are eligible to receive government-funded healthcare – everyone else is expected to have their own health insurance, or face huge medical bills and a tax penalty.

US government statistics show that in 2016, 65 per cent of people under age 65 had health insurance, and a NerdWallet Health study from 2013 found medical bills were the No.1 cause of bankruptcies in the US.

Ms John has an American friend who had to start a Go Fund Me campaign to raise $US250,000 ($319,000) because his US insurance didn’t cover the specialist who could remove his brain tumour.

“I just think the hospital is negligent in charging so much money,” Ms John says.

Although Ms John found US health care was “pretty good”, and sometimes “overkill”, she struggled to find available specialists for her child covered by her insurance, and often had to pay up to $US700 ($890) per month to see “out of network” doctors.

At one point I rang around places in Australia and we were going to go back to to treat her there, because it would be much more cost effective, even without Australian health insurance.”

Australia’s Medicare provides subsidised or free health care at public hospitals for all Australians, funded through taxes, and the Australian government offers financial incentives to Australians who buy health insurance.

Australian Institute of Health and Welfare statistics show that since 2009, almost half of Australians (45 to 47 per cent) had health insurance.

Australian expat, Laura (last name withheld), also encountered costs not covered by her insurance when she broke her arm and tore a ligament while living in New York City in 2016.

“They did (a) nerve block while I was anaesthetised which had the effect of totally numbing my whole arm for 24 hours and tried to charge me $US1200 ($1530),” Laura says.

“I was only told about it when I woke up, and only saw the cost weeks later when I was mailed the bill.”

Overall, Laura felt uninformed throughout her treatment, but was pleased with the result.

“The worst was not having much information on treatment, costs … and trying to work it all out in a new country with a system we haven’t used before,” she says.

Elisabeth Schuler founded Patient Navigator LLC, a company which helps people navigate the complex US health system, and says patients should make sure they understand exactly what their insurance covers and what it doesn’t.

“The patient must be meticulous in checking their medical bills … and follow-up with the provider and insurer should there be any questions, errors or discrepancies,” Ms Schuler says.

She recommends people moving to the US look for the most comprehensive health insurance they can afford, if their employer does not provide it. Tourists should organise travel insurance which covers health care before travelling to the US.