Health funding needs an extra $1.1 billion this year just to maintain current care and cover additional costs, according to research completed by the senior doctors' union and Council of Trade Unions.
That amount is on top of the $16.14b allocated to the wider health sector last year and covers population growth, salary costs, inflation and recently announced initiatives such as doubling of ambulance crew, boosts to Pharmac and the equal pay settlement.
It does not include any additional funding for care some say is missing from health.
With the 2017-2018 Budget to be announced on Thursday New Zealand Council of Trade Union's economist Bill Rosenberg said more was needed to cover extra commitments.
"Strictly speaking it is $721 million to keep things as they are but the government has committed to extra commitments that take it up to $1.1b," Rosenberg said.
"The government has committed to a number of other expenditure such as the equal pay settlement, mental health and doubling of the ambulance crew and that is going to cost an extra $1.1b," he said.
The squeeze on the health vote had been happening since 2010-2011.
To restore funding to that level Rosenberg said health needed a shot in the arm of $2.3b extra - taking it to $17.6b.
He said if the extra funding wasn't allocated problems would pop up elsewhere.
"In the past they have announced new services but they haven't provided the funding and the DHBs have had to find that money from somewhere," he said.
"They find it by cutting other services, not doing maintenance on their buildings, not replacing people that sort of thing."
He said underfunding was seen in waiting lists for people with eye problems and with primary services such as youth mental health.
"In some cases these services are squeezed so much they are disappearing because of the constant pressure on their funding.
"These services are the ones that stop people from getting to the stage they need hospital care."
Even with a $1.1b boost there is still essential funding needs that will not be met, said Simon Oosterman from the Public Service Association.
The PSA-run Yeswecare.nz campaign had seen New Zealanders such as Colette Smith and her family share their stories of services that were not funded.
Smith's son Otis, now 2, was born with a virus that caused complete deafness in one ear and partial deafness in the other.
Funding for cochlear implants is currently only available for children who are deaf in both ears.
A cochlear implant is a surgically implanted electronic device that provides a sense of sound to a person who is severely hard of hearing or profoundly deaf.
Despite having funding for a hearing aid for Otis's partially deaf ear there is no funding for an implant for his completely deaf ear.
The Pukekohe family baked cakes, sold superhero outfits, ran quiz nights, had a community garage sale and set up a Givealittle page to raise $50,000 for an implant for their son.
"I'd love for the budget to allow for this because all children should start off with the same opportunities.
"It doesn't make sense that there is funding for two implants but not for one."
The family were heavily supported by the charity Hearing House, which provided ongoing care and support.
"If it wasn't for them and our community I don't know what we would have done."
• Each year the ministry funds up to 16 newborns and 30 children for bilateral (one in each ear) implants
• Each cochlear implant costs about $45,000 for surgery, implant and switch-on.
• Total funding provided to the cochlear programme this year is $8.43m
• Budget 2014 provided additional funding to provide bilateral cochlear implants for children. Previously children received funding for a single implant only.