The first will begin from midnight tonight. It means people will be able to meet up outdoors with others from outside their bubble with no more than two households and 10 people getting together at a time.
At step two, more retail will re-open as will public facilities like swimming pools and zoos.
Step three opens the door for cafes, pubs and restaurants but customers must be seated and separated. Close contact businesses like hairdressers can also get back to work.
Cabinet will assess the impact of each phase before moving to the next.
ACT Party leader David Seymour said the Government should have set a clear timeframe.
"Then put the pressure on people to get vaccinated and on itself to prepare its defences to minimise transmission, hospitalisation and ultimately deaths from Covid-19 by equipping the health care system and every sector of the economy to reduce transmission, hospitalisation and death."
While the Prime Minister didn't explicitly call time on the elimination strategy, the Government's plan marks a clear move away from it.
National Party leader Judith Collins said Ardern needed to admit the Government had changed direction.
"New Zealanders are not children, we no longer believe in Santa. It's time that we were told the truth, the elimination strategy is quite clearly dead."
Collins also wants saliva surveillance testing in the community, rapid antigen testing introduced at the Auckland border, and a vaccine target introduced.
The shift in strategy comes as vaccination rates among Māori are only about two-thirds of those of the general population.
Te Paati Māori co-leader Debbie Ngarewa-Packer said the roadmap doesn't take that into account.
"This roadmap has been designed as if we have all arrived at the beginning of the track together, but we haven't.
"Some of us aren't even at the beginning of this roadmap, so where is the mitigation for the well-known, highly publicised, highly recognised inequities."
Green Party co-leader Marama Davidson said the Government's decision puts thousands of people at risk.
"The elimination strategy and the zero tolerance for Covid-19 is the right one, especially for people who are behind, who are more at risk, who are behind in vaccination."
Ardern says the change in strategy was always going to happen, but the Delta outbreak has accelerated it.
The country will remain in the transition phase until vaccinates rates increase.
But there's a lot of work to do - with the number of people getting their first dose trailing off to just 7000 on Sunday.