People suffering from a terminal illness can now ask for medical help to end their lives.
The End of Life Choice Act was put to a binding referendum at last year's election and gained 65.2 percent support.
It came into effect yesterday - exactly one year later.
For Bobbie Carroll, who has terminal cancer, the law has always been about simply allowing choice.
"Every Kiwi in New Zealand was a winner when this went through. No one is forced to do anything. Anyone that wants assisted dying can have it and people that don't want to do not have to avail themselves.
"It's one of the few times when legislation or a referendum ends up with everyone being a winner and it's just brilliant."
But palliative care expert and anti-euthanasia group Care Alliance spokesperson Sinead Donnelly said the legislation made a mockery of choice.
"We're told that the Ministry of Health apparently had about 40 people contracted or working on this End of Life Choice Act. You know, there's nobody in the Ministry of Health overseeing the development of palliative care, so what choice is that truly.
"If people are burdened by symptoms and distress and have an inadequate palliative care service in their region for whatever reason and as a result their distress becomes intolerable and then they request this - that wasn't a real choice.
"The fact that palliative care, 50 per cent of its funding in this country depends on op shops and cake sales and fund-raising ... and the Ministry of Health is fully funding the End of Life Choice Act. So - what choice is that?
Carroll disagrees. She said sometimes even those with best end of life care, eventually have enough.
"This is for serious illness, serious situations. Where people have just had enough. They are dying, nothing is going to change the fact that they're dying and it's about how they die."
The eligibility test includes only having six months to live and being of sound mind.
The person must also be over 18 and be a citizen or permanent resident.
Two doctors must be involved - one of them appointed by the Ministry of Health's SCENZ oversight committee.
A psychiatrist can also be called in if there are any uncertainties.
A health practitioner cannot initiate any conversation about euthanasia and the person can change their mind at any time.
Ninety-six doctors have expressed an interest in helping those patients who want to die.
Based on overseas experiences, the ministry estimates up to 950 people could apply for assisted dying each year, with up to 350 being assisted to die.
Now that it is legal, for Donnelly and the Care Alliance, the focus is now on making sure it does not operate in the shadows.
"The most important thing is data collection. So we have engaged with, or tried to engage with, the Ministry of Health to determine what data they will collect around why a patient would choose this assisted suicide.
"So if the purpose of this legislation was simply choice you don't actually have to collect any data because that doesn't matter but if the focus is also on safety and safeguards ... then it's imperative to collect data from the beginning."
More data than what they had been told would be collected, was required, she said.
"In Oregon, the data is collected about whether it's due to physical pain, loneliness, fear of pain, fear of being a burden, fear of institutionalisation.
"Also data like, how did the health care practitioner determine that the prognosis was less than six months? How did they determine the intolerable suffering? And what was the cause of that suffering? Did they know whether the patient had mental health issues? Did the patient have a recent bereavement ... all these factors could impact on the person's decision to request this."
Before ACT deputy leader Brooke van Velden was elected to Parliament, she played an instrumental role in getting party leader David Seymour's End of Life Choice bill across the line.
She said it had been a long road.
"This weekend New Zealand became a kinder, more compassionate and humane society for allowing people who are struggling and suffering in those last few days with their terminal illness.
"Choice and compassion on how and when they go - I think that's what we should have."
Ministry of Health will fully fund the costs associated with end of life choice.
RNZ asked the ministry about what data it plans to collect, but had not received a response at the time of publication.