Other St John shuttle services affected cover Pahiatua, Horowhenua, Feilding and Whanganui, and the local health shuttle for Levin and Foxton/Foxton Beach.
MidCentral District Health Board chief executive Kathryn Cook said the board was working with the shuttle providers to minimise disruption to patients.
"All efforts are being made to ensure any patients who require transport to the hospital are being supported."
Cook said the DHB was working closely with St John and other transport providers and would advise the public of any changes to the situation.
"We have arrangements in place to transport those patients who need to attend hospital."
She said each patient was being contacted directly to provide guidance and advice, and a plan was being made for each.
"We are working with St John and with our other shuttle service providers to confirm arrangements and we will ensure essential patient travel is maintained."
She said the DHB was contacting each patient directly about their upcoming appointments.
"We have also established a team of staff who are taking patient queries about appointments and managing these directly with the clinical team concerned."
Some non-urgent appointments had been postponed and many patients were receiving advice by telephone.
"We are prioritising the patients who are required to come to the hospital for treatment and are continuing to provide essential health services to our population."
In Dannevirke there were four patients who received dialysis treatment three times a week and arrangements had been made to transport them to hospital.
St John regional community programmes manager Julie Taverner said St John was looking at alternatives.
"It's really sad for the volunteer drivers as a lot of them still want to continue with the shuttle service."
She said some of the shuttle vehicles may have to be deployed elsewhere.
The St John patient transfer and urgent services would continue at this stage.
Patients who have any queries about the shuttle services they use can contact Palmerston North Hospital on 06 356 9169.