The emergency department at Roscommon County Hospital is to close from next Monday.
It will be replaced with an urgent care centre and an out-of-hours GP service at the hospital.
Staff and local politicians are being briefed on the development this evening at the hospital.
Minister for Health Dr James Reilly last week described the Roscommon County Hospital emergency department as unsafe.
The urgent care centre will treat fractures, sprains, minor burns and wounds.
The GP out-of-hours service will operate at the hospital from 6pm until 8am.
A medical assessment unit will operate from 9am to 5pm weekdays treating chronic conditions.
Emergency cases will be handled by nearby hospitals in Galway, Sligo and Mayo.
An enhanced ambulance service will also be established with extra crews.
The Minister for Health has told the Opposition that their motion seeking the retention of emergency services at local hospitals is seeking to sustain something that is unsustainable.
James Reilly said he did not accept that changes to the emergency department at Roscommon represented a downgrading of that service
He said he saw the new urgent care unit as the beginning of a new lease of life for the service.
Minister Reilly added that the mortality rate for a cardiac patient was four times greater in Roscommon than that at the closest centre of excellence at Galway.
Sinn Féin's Caoimhghín Ó Caoláin said the Government is breaking its commitment to retain hospital services.
Mr Ó Caoláin said that after Roscommon hospital was downgraded, the axe would fall elsewhere.
The Roscommon Hospital Action Committee has condemned the behaviour of a protester who disrupted train services from Galway and Westport for three hours this morning.
The protester climbed to the top of the railway bridge over the river Shannon in Athlone with a banner.
Committee chairman John McDermott said the group had no prior knowledge of the man's intention and wished to disassociate themselves from his behaviour.
Mr McDermott said a number of train passengers had been travelling for hospital appointments in Dublin and had their plans disrupted.
This was the last thing the hospital action committee would want, he said, and he urged protesters not to engage in any similar activities.
The committee does plan to protest at Leinster House tomorrow and stage a demonstration on seven bridges crossing the River Shannon two days later.