MidCentral District Health Board is offering a $20 grocery voucher to people who return its pulse oximeters.
The small device is used to monitor the condition of people who have Covid-19 and are at high risk of serious illness.
The DHB is running low because of increased demand during the Omicron outbreak.
It says the devices could save lives, and has set up return sites in Palmerston North, Tararua, Manawatū, Horowhenua and Ōtaki.
Acting Covid-19 senior responsible officer Dr Kelvin Billinghurst said the DHB wanted to build up its stock of the devices before winter.
It had about 350 pulse oximeters, and about a third of these were due for return.
Billinghurst said said while the DHB was grateful to those who had already returned the devices, it was difficult for others in remote locations.
"Many people who have the products at the moment, they are in isolated and remote communities," he said.
"The incentive is a small token for their efforts that they will be making to get these items returned."
Billinghurst said some of these areas even had difficulty accessing postal services.
He said the grocery voucher was also a broader way to meet the needs of the community and deliver healthcare.