Secretary General of the Department of Health Ambrose McLoughlin is to step down from his role shortly, RTÉ News has learned.
Dr McLoughlin was appointed as Secretary General in April 2012.
He will continue until a successor is appointed by the Government.
Dr McLoughlin's decision to step down is a personal one.
Next year, he will have been in the public service for 40 years.
Among the key areas he was involved in at the department were moves to improve the retention and training of doctors, the development of hospital groups and reference pricing to bring down the cost of medicines.
He will move to a new role supporting the Healthy Ireland initiative.
Dr McLoughln was previously Chief Executive of the Pharmaceutical Society of Ireland and was CEO of the North Eastern Health Board.
From January next year the Department of Health takes back the accounting officer role from the HSE, which means it will have direct responsibility for all spending and resume its accountability role that existed up to 2004.
Minister for Health Leo Varadkar paid tribute to Dr McLoughlin saying he looks forward to continuing to work closely with Dr McLoughlin in his new role.
He said he expects to rely on his counsel and advice into the future.
Mr Varadkar said Dr McLouhglin's "extensive experience in the health arena will provide invaluable insight and guidance in progressing the achievement of the goals set out in the Healthy Ireland framework".
Dr McLoughlin said it has been a privilege to serve as Secretary General in the Department of Health and he is "very proud to take up this new role".