THE health service spent more than €8.4m last year re-hiring hundreds of its retired staff who are on generous public service pensions.
The pensioners included 266 nurses, coming at a time when many of their youngest colleagues were forced to emigrate due to lack of jobs.
They also included 80 doctors, three dentists and 23 health and social care professionals.
Among the 514 rehired were 30 managers and administrative staff, 25 who were involved in patient care and 87 support workers.
The information was obtained in a parliamentary reply by Roscommon Independent TD Denis Naughten.
Mr Naughten was told the pensioners were needed to ensure there was continuity of safe service in "critical service delivery areas".
They were called on in instances where particular skills were urgently needed. They also filled in while new staff were being recruited over a short to medium term.
"This would typically include consultant medical staff hired to cover their previous post while a replacement was being hired to cover their previous post," said the HSE's corporate finance manager John Leech.
They also involved skilled psychiatric nursing staff who were difficult to replace.
Some of the payments were fees they received for sitting on recruitment panels interviewing job applicants.
He said that although they were on a pension, they were liable to have it reduced while back working. This is because of the rule which states that the sum of the pension and wages cannot be more than the regular salary for the post.
The revelations come as Professor Trevor Duffy, president of the Irish Medical Organisation (IMO), warned that the outlook for the health services was increasingly bleak.
"Our public health services have been starved of adequate funding at a time when there is increasing demands and an ageing population.
"We have been warning for many years that the situation is simply not sustainable. The political squabbles which now surround the health services are causing huge anxiety and worry amongst patients and front line staff.
"There is a real sense of policy drift and concern that sufficient resources will not be made available to deal with demand levels and to ensure health professionals are treating patients in a safe way."