The first in a series of substantive announcements about the current tender for national air ambulance services is expected to be in late September.
The Ministry of Health and ACC's tender process, currently under way, is being described as "a first step towards a 10-year modernisation programme for air ambulances".
The tender process has now moved into formal negotiations with three preferred tenderers across three regions: Northern, Central and Southern.
The negotiations remain confidential until they are concluded.
The Ministry of Health says the negotiations are aimed at ensuring the new services will deliver a nationwide service for all New Zealanders, and be more integrated with road ambulance and hospital services.
"Air ambulance services are more than a transport service. They play a critical role in how we respond to health emergencies," says manager community and ambulance Andy Inder.
"A good air ambulance service has four key elements: optimal time, appropriate clinical crew, the right equipment and the right destination. With these working together well, patient outcomes can be improved.
"That's why we are taking the time to work with the preferred tenderers, as well as district health boards, to ensure patients needing urgent clinical support get the right clinical care at the right time."
The agreed providers for each region will be announced as the negotiations are concluded. The first announcement is expected later in September.
NASO, the National Ambulance Sector Office, is managed jointly by the Ministry of Health and the Accident Compensation Corporation (ACC).
Both the Taupo and Rotorua rescue helicopter bases were left off NASO's original request for proposals for air ambulances, prompting local protests. In the Central Plateau area widespread concern has been expressed about the impact on people needing urgent search and rescue help if there is no local helicopter available.