· In short: From July, South Australian GP clinics will pay payroll tax for doctors employed there.

· The change has been opposed by the Royal Australian College of GPs, but the government says some clinics have been avoiding tax obligations.

· What's next? The SA treasurer will meet with GPs in coming days.

If going to the doctor becomes more expensive for Colin Dent, it wouldn't necessarily deter him from making an appointment.

But the 74-year-old from Adelaide's southern suburbs worries that paying more for GP consultations is a luxury not everyone can afford.

"When they talk about gaps, if you've got a $10 gap on some things, people basically wear that," he said.

"But once it starts to creep over $25, then it becomes significant.

"I wouldn't do it, but there may be patients who decide just not to go and that, I think, is the big problem."

Mr Dent, who lives with a disability and multiple health conditions, is concerned about the impact of an impending change to GP payroll tax arrangements on medical bills.

South Australia's premier and treasurer have defended the change, which follows a New South Wales tribunal ruling in 2022 that, by deeming doctors as employees instead of contractors, prompted a re-interpretation of payroll tax obligations.

Treasurer Stephen Mullighan has previously said some GP businesses had been "structured in a way" that has allowed them to "avoid paying payroll tax obligations".

As a concession to local clinics, the SA government agreed to a year-long amnesty that has delayed the implementation of the change, but that amnesty will expire — and the change will come into effect — from July 1.

Mr Dent's concern is that, since the extra costs are likely to be passed on by doctors, changes to current arrangements would have the effect of discouraging patients who are most in need from seeking treatment.

"It's an unfair tax in the sense that the people who are going to be affected are the most vulnerable," he said.

"If we're going to have a payroll tax, OK fine … but the thing is, we've got to have a way of compensating.

"These businesses are there to provide a service for the vulnerable, the people with chronic conditions. Those are the people who say, 'I need to see my GP or I need to speak to my GP'."

'Downstream effects in EDs'

Mr Dent is a patient of Adelaide GP Daniel Byrne, who, along with other members of the Royal Australian College of GPs (RACGP), has been a vocal critic of the payroll tax change.

Another doctor to have spoken out against it is Vikas Jasoria, who said the repeal of the amnesty would threaten the viability of clinics.

"All medical centres are small businesses and if we do not have a small business because they take all profitability out of them, there's no reason for the clinic to be functioning here, and the 1,500 patients we see a week will no longer have a doctor to see," he said.

"The downstream effects will be [that] patients will be ending up in the ED [emergency department], and there'll be an increase in ramping issues.

"The average cost of a GP consult is around $40, whereas every time you go to the emergency department it costs $600 to the government. It's a no-brainer that general practice is the best way to look after our population."

The SA government has committed to meeting with the RACGP to discuss the issue.

"The state government, particularly the treasurer and also the health minister, has been very keen to work collaboratively with representatives of GPs throughout the state," Premier Peter Malinauskas told parliament this afternoon.

"The amnesty arrangement that has been in place is very, very different from what we see happening in other states such as Victoria, where no such arrangement is available."

Mr Mullighan told parliament there had been "extremely productive" interactions with the RACGP so far.

"I remain in regular contact with the Royal College and my office advises me that we're due to meet in the coming days to continue these discussions," he said.

"We have made a series of decisions as a government to put in place a regime which is far more generous to GPs than what is happening in some other states and territories.

"The reason why is because we recognise … the critically important role that GPs play in our community."