1904 - Old Age Pensions Department established.
1909-1912 - Pensions administered as a division of the Post and Telegraph Department.
1913 - Pensions Department established.
1 April 1939 - Social Security Department under the control of Social Security Commission was established by the Social Security Act, 1938. It replaced the former Pensions Department and absorbed the major portion of the Employment Division of the Department of Labour.
1 April 1972 - Department of Social Welfare formed from the amalgamation of the Social Security Department and the Child Welfare Division of the Department of Education.
1 May 1992 -Major restructuring of the Department of Social Welfare into business units:
- New Zealand Income Support Service
- New Zealand Children and Young Persons Service
- New Zealand Community Funding Agency
- Social Policy Agency
- Corporate Office
December 1998 - Housing policy function of the Ministry of Housing transferred to the Social Policy Agency of the Department of Social Welfare.
1 October 1998 - Department of Work and Income (branded as Work and Income New Zealand or WINZ) established with the merger of Income Support with the New Zealand Employment Service, Community Employment Group and Local Employment Co-ordination.
1 October 1999 - Ministry of Social Policy established, with the amalgamation of the Social Policy Agency and Corporate Office functions of the former Department of Social Welfare and the addition of the new Purchasing and Monitoring Group.
1 October 1999 - Department of Child, Youth and Family Services (CYFS) established. Was previously Children, Young Persons and their Families Agency (CYPFA).
1 July 2001 - Housing Policy function of the Ministry of Social Policy moves to Housing New Zealand Corporation.
1 October 2001 - Ministry of Social Development established with the amalgamation of the Ministry of Social Policy and the Department of Work and Income.
1 July 2006 - Child, Youth and Family becomes a service line of the Ministry of Social Development.