Prime Minister Malcolm Turnbull has vowed Medicare won't ever be privatised but says the 30-year-old payment system does need to be updated.
He said that was a matter of bringing government services into the 21st century and the smartphone era but even an updated payment system would not be outsourced.
Mr Turnbull said Opposition Leader Bill Shorten's claim that the coalition planned to privatise Medicare was the biggest lie of the election campaign.
"Every element of Medicare's services that is delivered by government today or undertaken by government today will be undertaken by government in the future," he told ABC TV's Q&A program.
Mr Turnbull said there had been consideration of updating the Medicare payment system but no decisions had been made.
"I'm saying to all Australians, unequivocally, as PM, that no part of Medicare that is delivered by government today will be delivered ... by anyone else in the future," he said.
That included the payment system, he said.
Mr Turnbull said he remained sceptical about the way government information technology services had been outsourced in the past, with efficiencies less than promised.
But government services did need to be brought into the 21st century.
"You don't do that solely by pushing them all out the door so that there is nothing left inside government," he said.