A pill to prevent the spread of HIV could save taxpayers more than $120 million, says the Aids Foundation, which is calling on politicians to promise funding.
Pre-exposure prophylaxis, or PrEP, would cost $2.4m a year to fund for the highest risk group of men who have sex with men.
But if new infections continue at the same rate, lifetime treatment for the same group, at $800,000 a person, amounts to $127m.
Funding PrEP and increasing testing would help New Zealand reach its target of no new HIV transmissions by 2025, foundation chief executive Jason Myers said. It protects the individuals who take the pill and their future sexual partners.
"Not only does an HIV diagnosis have a significant impact to the individual but it's a significant burden on the New Zealand health system.
"The opportunity [to end new HIV diagnoses] is there, the sector just needs to be sufficiently resourced."
Myers said to make a difference it would only need to be funded for about 4000 men who are very sexually active. HIV has a window period of four to 12 weeks where a person can be infected with HIV and be infectious but still test HIV negative.
"If you get to the middle of that very dense network and put a barrier in place it can have a significant flow-on effect."
The highest number of people recorded, 244, were diagnosed with HIV in New Zealand last year since records began in 1985. Of those 159 were men who have sex with men.
Wellington man Vaughan Meneses contracted HIV 13 years ago but wasn't given treatment until he ended up in hospital with pneumonia. These days he takes antiretroviral therapy and his level of the virus is undetectable.
Meneses, 50, is speaking out to raise awareness around prevention and the stigma associated with HIV. If PrEP had been available at the time he would have taken it.
"No one really wants to rush out and get themselves a chronic illness if they can avoid it. PrEP means you're protected all the time. The fact it is available but not funded is ridiculous.
"Condoms only work once they are in the right place. Most people don't put a condom on when they are still wearing their undies."
Health minister Dr Jonathan Coleman said the National party supports the move to make New Zealand HIV-free. The Government has increased Pharmac's budget by $220m since 2008 but Coleman said funding decisions were up to Pharmac.
This year the Ministry of Health cut funding for a study on new trends in HIV diagnosis.
Labour leader Jacinda Ardern said her party was absolutely committed to ending HIV transmissions by 2025 and would fund access to PrEP.
"This is a small investment which will protect the health of New Zealanders and will save millions in lifetime treatment."
It has previously cost as much as $1000 a month to buy PrEP in New Zealand. But the drug's patent had just finished, which meant it would get down to $50 a month or cheaper, Myers said.
Other countries have already decided that PrEP is a cost-effective way to deal with HIV. New South Wales Health have 6000 people on funded PrEP and the UK Government will offer the drug to 10,000 "high risk" people from next month.
The European Parliament passed a resolution calling for PrEP to become widely available across Europe and the World Health Organisation has added the drug to its list of "essential medicines".
• $600/year for 4000 at risk men = $2.4million
• 159 high-risk people diagnosed with a lifetime cost of $800,000 each = $127.2million