Senior doctors are blaming underfunding and poor decisions for the district health boards' deficit blowout.
At the end of December, the country's 20 DHBs expected their collective year-end deficit to be $178 million.
That figure has since risen to $189m, and health officials say financial pressures, including a nurses' pay settlement, could push it up to $225m.
The senior doctors' union blamed underfunding by the National-led government and some poor decisions by DHBs regarding the deferral of maintenance.
The executive director of the Association of Salaried Medical Specialists, Ian Powell, says eight years of under-funding of health by the former government is to blame.
"I think that's ultimately where the bullet has to be directed at: under-funding and poor leadership government," he said.
"Also, district health board's themselves have been rather like possums in the headlights over this and have made some poor and short-sighted decisions because of that pressure," Mr Powell said.
Health Minister David Clark declined to be interviewed on Friday or today.
However, he said in a statement that the size of the DHB deficits should come as no surprise, given systematic under-funding of health by the previous government.
Mr Clark said he's made clear to DHB chairs his expectation that they are careful stewards of health funding and must take care to contain costs given current constraints.
He reiterated government commitment to well-funded public health service but said it's not possible to achieve everything in its first budget.
National's health spokesperson, Michael Woodhouse, rejected the under-funding claim: he said the total DHB deficit was less on his government's watch than it was under nine years of the Labour government before that.
He said under the National government there had been high levels of throughput and less industrial unrest.