Mr. Mark Byers has been the Chief Executive of the New Zealand Corrections Department from 1995 and has overseen a range of significant organizational development initiatives and also major changes to the way in which offenders are managed. In August 2004, Mr Byers announced he would retire from the public service in February 2005.

His started his career as a public servant in the Department of Agriculture where he was involved in human resources and industrial relations work. He then went to the State Services Commission and during the period of 1985 to 1987, he was responsible for a number of machinery of government changes, including the review of environmental administration agencies, the establishment of State-owned Enterprises. He also coordinated expenditure review activity as part of the Budget setting process. In 1987, he moved to the Treasury as Deputy Secretary (Corporate Services) and thus Chief Operating Officer for the department. This entailed overhauling internal management systems and reshaping the department. Between 1990 and 1993 he was Chair of the Officials Committee on Expenditure Control working with the Treasury Ministers. He also had involvement in aspects of Public Sector management reform over that period, including being a member of the Officials Committee for the State Sector.