The Office of Retirement Services administers retirement programs for Michigan's state employees, public school employees, judges, state police, and National Guard. ORS serves over 530,000 customers including approximately 278,000 active, and 256,000 retired members representing approximately one out of every fourteen Michigan adults, including customers living in approximately one out of every nine Michigan households.

Within these systems, ORS administers four defined benefit pension plans, two defined contribution pension plans, and one defined benefit plus a defined contribution plan with combined net assets of nearly $50.54 billion. ORS is responsible for the 16th largest public pension system in the US and the 48th largest pension system in the world. In fiscal year 2012, ORS paid out over 6.65 billion in pension and health benefits

ORS is a division of Michigan's Department of Technology, Management and Budget.