The Auckland District Health Board is seeking clarification from the Ministry of Health about eligibility criteria for aged care residents after complaints from the sector.
The complaints arose after the board wrote to the region's rest homes, including hospital wings and dementia units, asking providers for patients' passports or birth certificates to prove they have residency.
Aged Care Association chief executive Martin Taylor says the letters were in response to a request from the ministry that health boards only deliver services to people who are New Zealand residents.
But the ministry is distancing itself from the board's actions, saying checks on residency status should be done before a person enters an aged care facility.
Mr Taylor says the board's request is unnecessary, because almost all aged care residents receive New Zealand Superannuation, which requires proof of residency.
The board says it is working with the ministry on how the policy should be implemented.