More than one million Australians put off seeing a GP or medical specialist last year because the bills were too steep, a report has found.
While Australians forked out $3 billion to cover "gap" payments for specialist medical services during the year, the cost of seeing a non-bulk billing GP was too expensive for 663,000 people.
Another 538,000 put off seeing a specialist because of the cost, while another 274,000 didn't get a pathology test or diagnostic image for the same reason.
The figures are contained a new Australian Institute of Health and Welfare report outlining the out-of-pocket costs for patients using non-hospital Medicare services including GPs, obstetric and medical imaging during the 2016/17 financial year.
Half of all patients who used those services - 10.9 million people - had to cover some of the cost because it wasn't all subsidised by Medicare.
The median out-of-pocket costs for patients was $142, but varied greatly across the country.
For some patients in northern Sydney, those out-of-pocket costs hit $876 - six times the median.
"A range of factors can influence out-of-pocket costs," AIHW spokesman Michael Frost said.
"These can include the types of services the patient requires, the availability of bulk billing and the cost of services in their area."
Most of the $3 billion patients spent on out-of-pocket costs during the year was paid to specialists (34 per cent), followed by GPs (25 per cent), and diagnostic imaging services (12 per cent).
But it was obstetric services that had the biggest variations in out-of-pocket expenses.
Of the 3361,000 people who used out-of-hospital obstetric services, 44 per cent paid part of the bill.
However the median out-of-pocket costs for patients in northern Sydney ($227) were more than 10 times that in Gippsland in Victoria ($21), while some patients in the Northern Territory forked out $887.
Nearly three quarters of patients who saw a specialist didn't have their bills fully covered by Medicare, spending about $64 per appointment.
For those who paid to see their GP, the out-of-pocket costs ranged from a low of $12 in western Sydney to $51 in Canberra.
Median costs for diagnostic images also ranged from $25 in western NSW to $90 in Canberra.
MIND THE GAP FOR MEDICARE SERVICES
* 10.9m people incurred out-of-pocket costs for non-hospital Medicare services in 2016/17
* The median amount spent was $142 per patient
* The 10 per cent of patients with the highest costs spent at least $601 or more in the year, ranging from $432 to $876
* Patients were more likely to pay for specialist and obstetric services, which had the highest out-of-pocket costs
* 1.3m people said cost was the reason they delayed or didn't seek specialist, GP, imaging or pathology services
Australian Associated Press