Rhuddlan GP surgery to close from April 2016
A third GP surgery in Denbighshire has announced it will end its contract with health board bosses next year.
The decision by Rhuddlan Surgery leaves more than 22,000 patients uncertain who will provide GP cover from next April.
Doctors at the Pendyffryn Medical Group and Seabank Surgery in Prestatyn terminate their contract in March, blaming the problem on recruiting GPs.
Betsi Cadwaladr University Health Board said it would ensure patients continue to have access to a GP service.
It has had to take over three other practices in north Wales in the last 18 months due to GP shortages.
Practices can be managed by GPs who run them as their own business or by GPs employed by health boards directly.
A spokeswoman said: "The Rhuddlan Surgery has recently given notice that they wish to withdraw from their contract to provide NHS services.
"Arrangements are being made to write out to every patient with the practice to inform them of this and to reassure them that they will still have access to a GP service.
"Over the coming weeks the health board will be looking at the options for providing this service."
The health board currently runs three practices in Wrexham, Conwy county and Gwynedd.