Mr. Pengelly has moved to the same role in the Department of Justice, which until now was occupied by Mr. May.
Mr. Pengelly was appointed to the Department of Health top post in 2014.
Health Minister Robin Swann said: “I want to thank Richard for his years of dedicated service to health and social care. His time as Department of Health Permanent Secretary has witnessed a global pandemic as well as three years without a Health Minister. He has worked relentlessly and with great commitment throughout these challenging times. I wish him well in his new role.”
Michael Bloomfield, chief executive of the NI Ambulance Service and chair of the Northern Ireland Confederation of Health and Social Care (NICON), said: “I know from personal experience how supportive Richard has been to Trusts during very challenging and turbulent times. My colleagues and I extend our best wishes for the future and thank him for the leadership he has provided over many years in the Department of Health.
“We know he has undertaken his responsibilities with diligence and dedication, always committed to driving better outcomes for our citizens."