While traveling in New Zealand you will be covered for injuries by NZ Government ACC agency (Accident Compensation Corporation)

In simple terms this means, if you are injured you will be able to make a claim and part of your medical costs will be paid by the government.

NOTE: It is recommend that you purchase travel insurance as ACC will not assist you if you suffer from illness not related to injury or have to travel back to own country for medical assistance.

For full information, please read the ACC Website
Link: "Injury while traveling in NZ"