National Health Index overview

The National Health Index number (NHI number) is a unique number that is assigned to each person who receives healthcare in New Zealand.

The NHI is an index of identity information associated with that unique number. The Health Information Privacy Code 1994 places restrictions on the creation and use of unique identifiers such as the NHI number.

What information does the NHI hold?

The NHI holds the following information:

  • name (including alternative names such as maiden names)
  • NHI number
  • address
  • date of birth
  • gender
  • New Zealand resident status, place of birth and citizenship status  (this is dependant on what application or service is used to access the NHI 1)
  • ethnicity
  • date of death (if appropriate).

Clinical information is not recorded on the NHI.

This information allows individuals to be positively and uniquely identified for the purposes of treatment and care, and for maintaining medical records.

Healthcare providers can be sure that they are talking about the same person, thereby reducing the chance of making a clinical decision based on wrong information. This certainty is increasingly important as patients become more mobile, when care occurs in both the primary and secondary sectors, and where emphasis is on ‘shared’ care.

Why is the NHI important?

The NHI and the NHI number are central to the vision of safe and secure sharing of information among health providers. An NHI number is fundamental for services to link information and get a better understanding of each person’s needs.

The complexity of hospital care and the wide variety of primary care providers has led to the development of independent clinical information systems, such as pharmacy, laboratory, and admission/discharge/transfer. Important information relating to an individual patient is often held in more than one place. The NHI number allows all this information to be brought together.

A detailed account of how the NHI number can be used is available in the NHI and MWS statement of use.

Who has access to the NHI?

Health providers listed in Schedule 2 of the Health Information Privacy Code are allowed to access the information in the NHI. All authorised providers must comply with the provisions of the Privacy Act and Health Information Privacy Code when accessing and updating information in the NHI.

The Ministry assigns appropriate permissions, and monitors and audits the actions of health provider use of the NHI. Some health providers have limited access and can only view information; others are able to update information on the NHI.

Who keeps the NHI up to date?

Providers are responsible for ensuring NHI information is accurate and current. They will do so each time a patient presents for a health service and identity information has changed. They will contact the Ministry for assistance with any data issues they cannot correct themselves.


1. Following a review of the NZ  Resident field on the NHI, in 2011, the Sector Advisory Group and the Health Identity Project Governance group agreed the data was 'inaccurate and out of date, so cannot be relied upon for eligibility'. It was recommended that this field should be replaced by other ‘evidence of eligibility’ fields.  A decision was made to enable the storage of two key data elements to assist with the eligibility decision making process:

  • a) Place of Birth (locality and country)
  • b) NZ Citizenship Status

Place and country of birth, and citizenship status are able to be seen through our new web based service used by GP Patient Management Systems.  They are not yet visible to users of the NHI through hospital systems.

Hospital users continue to see the NZ residency field on the old NHI, but this is not visible to users of GP Patient Management Systems.

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