The public health watchdog says the health and disability system is basically sound, though constant vigilance is needed.
Health and Disability Commissioner Anthony Hill said in his annual report the office continued to manage a rising number of complaints, which was part of an international trend.
The authority resolved 1900 cases in the last year and treatment problems dominated complaints, he said.
Mr Hill said that included 115 investigations, 79 cases where patients' rights were breached, and 23 referrals for possible follow-up legal action.
He said a recurring theme for the year was about team work and communication.
He said he was constantly alert when assessing complaints as to whether there was a marker or pointer to a quality problem.
"As a general proposition though, I think we can be very confident in the quality of services general in New Zealand.
"With that comes need to be eternally vigilant to spot change and respond appropriately when we see warning signals."