A healthcare worker in Taranaki says budget savings made by Te Whatu Ora will compromise patient care.
Public hospitals have been asked to make savings of $105 million by July.
For Taranaki that amounts to $3.2m or 1.2 percent of their budget.
On Monday, Te Whatu Ora chief executive Margie Apa told Checkpoint hospitals had been overspending and this was about "getting back to budget."
But she said they were "not cutting services" and were still hiring frontline clinicians.
Te Whatu Ora chief Executive Margie Apa speaks to Lisa Owen
Health Minister Shane Reti had also previously said the budget target would not take away from the frontline for medical care.
But a healthcare assistant, who works at a hospital in the region, whom RNZ agreed not to name, said they had already noticed a reduction in the shifts they were being asked to do.
"The hospital have been screaming out for us to do extra shifts" for the past three years, he said.
But those extra shifts had suddenly stopped, despite the need still remaining, he said.
That raised questions on how the hospital would fill that need if it was not allowing its workers to do overtime, doubles or extra shifts, he said.
The solution appeared to be hiring less experienced casuals to fill the shifts, which would compromise patient care, he said.
"With them hiring more casuals, they're going to flood the hospital with new staff and who knows how well they're going to deal with the [patients' healthcare] demands."
The casual staff would not know the patients and their healthcare issues like regular staff, he said.
The healthcare assistant was also concerned consequences of the less experienced care could include longer hospital stays and increase morbidity rates.
But he said the casual staff were likely to be on a lower pay rate, thus providing the hospital a saving.
Te Whatu Ora has been approached for comment.