Most pre-existing conditions will be covered if members join by July 3. Insurance cover will go live from April 4.
Joining the scheme is free for registered members and all their insurance premiums and any payable excess will be paid by Ngati Whatua Orakei.
Royal said uptake was expected to be about 70 per cent, or 2,800 people and "any more than that would obviously be a great achievement for us".
Roadshows are being held to encourage people to sign up. Non hapu family members are also entitled to join the plan at their own expense and receive the added benefit of the pre-existing conditions element.
Nib New Zealand chief executive Rob Hennin told BusinessDesk a personalised plan was developed to meet the needs of the hapu members and "as such the premiums associated with the plan reflect the specific benefits and level of cover offered under each cover, while ensuring it remains value for money".
Hennin said the aim was to extend the scheme to other iwi: "We are excited about the possibility of working with other iwi Maori to deliver similar approaches to managing the future healthcare needs of their people."
The scheme also includes a health management and intervention programme that will let Ngati Whatua Orakei track and manage population health outcomes. The portal will allow identification of health trends to enable relevant and appropriate intervention, it said.
Nib has partnered with high profile Maori health advocate Lance O'Sullivan and his iMoko service to use modern technology options. According to O'Sullivan, prevention is better than the cure and a partnership with an insurer such as nib has the potential to encourage communities to remain well rather than have to access reactive health services.
In February, Nib Holdings' New Zealand unit said it boosted first-half profit after paying out fewer claims than a year earlier and after a smaller premium payback bill on its product which reimburses policyholders the difference between premiums received and claims paid.
The New Zealand division is the Australian insurer's smallest, accounting for 101,151 policyholders, or 12 per cent of the group's 816,676 policyholders.