A spokesperson for Health NZ said it was estimated that 86,000 people in Northland were impacted.
Health NZ said it would be ensuring support is available for those in the region.
Alex Pimm, group director of operations for Northland, said it was looking for funding to allow general practices to provide consultation.
He said it would be for those impacted to discuss their clinical information as well as for mental wellbeing support.
Those who are impacted by the data breach will also be provided with an 0800 number to call.
Pimm said Health NZ used ManageMyHealth in Northland to enable patients to access some documents – such as their hospital discharge summaries, clinic letters, and referral notifications.
“This system allows consumers, with or without a primary care provider, to access this important information,” he said.
“While Health NZ’s own data systems have not been compromised, any issue involving patient information is taken very seriously.”
Northland is the only area of the country where Health NZ uses ManageMyHealth to share information with patients.
- RNZ