The shortage of GPs is so bad some doctors are being abused over wait times or closing their books to new patients, General Practice Aotearoa says.
A Victoria University study has found 36 percent of general practices were not enrolling new patients last year and points to major workforce shortages and underfunding as the key driver.
General Practice Aotearoa chairperson Dr Buzz Burrell told RNZ the problem was reaching a tipping point for many.
"I'm seeing frustrated GPs who are being sometimes abused by patients and accused of all sorts of attitudes they're not carrying," he said.
He has worked for years as a GP in rural practices and as a pain specialist, and said with GP wait times ballooning and new patients being turned away, he feared for the health of New Zealanders.
"Early conditions are being missed or presenting late. We see poorly controlled hypertension, poorly controlled diabetes, late presentations of cancers, appallingly managed chronic persistent pain... we have a perpetuation of the opiod crisis," Burrell said.
"We've got people on sickness benefits who could be rehabilitated back to meaningful work if only we had the time and resources to do that - the list goes on. All of which are consequences of an underfunded primary healthcare system."
The study found with many GPs coming up to retirement age, it was increasingly hard to fill their roles, especially in rural areas. But it also highlighted problems with the current funding model, which has not changed in decades.
Burrell said this was a key issue, and 20 years of underfunding was now evident in the primary healthcare sector.
"Patients are suffering. The very patients who need to get in and see their doctor can no longer get in to see that doctor so they either wait way too long, sometimes many weeks, or they over burden our already overburdened emergency departments which are in turn going to be similarly underservicing and we are going to see mistakes being made.
"This is the predictable beginning of a collapse of our health system."
Newly appointed health minister Simeon Brown is promising primary healthcare access is a top priority.
"There's always more we can do and we must do that... and there is a range of factors behind what is needed to ensure Kiwis can access timely and quality care whether at the doctors or through emergency departments.
"That's my focus as minister of health," Brown said.
The minister said he will seek advice on the issue.