Under the scheme, patients from the Republic of Ireland will be able to cross the border for an out-of-hours GP service.
Similarly, people in Northern Ireland will be able to use nearby facilities in the republic.
In one pilot, patients from the Inishowen area of County Donegal will be able to use services from Western Urgent Care in Londonderry. In a second, patients from Keady in County Armagh will access out-of-hours from Castleblaney across the borders.
The scheme follows a feasibility study, which shows that some people in remote border areas would find it easier to cross the border for out-of-hours care.
The cross-border authority, Co-operation and Working Together (CAWT), which has representatives from health services on both sides of the border, believes that about 1,600 people from the republic will use the centre in Derry, while about 800 from Northern Ireland will use the centre in Castleblaney. CAWT project manager Leona Edgar said: 'This could be a model for European health.'
The two health services are trying to ensure data protocols are the same, so records can be shared. CAWT has also sought legal advice about registration of doctors and medical indemnity.
Western LMC secretary Dr Tom Black said GPs welcomed the scheme. 'It's beneficial for patients. It makes good sense.'