The situation as at end of April 2011
The ten strategic health authorities (SHAs) remain operative.
As at 15 April 2011 there are 146 Primary Care Trusts (PCTs) and five Care Trusts (CTs) in England after Solihull CT reverted to a PCT.
There were also minimal changes on 1 April 2010 when two PCTs were merged into one and another PCT converted to a CT.
CTs have similar duties to PCTs, except that CTs have responsibilities for social care as well as health care.
July to October 2006
Health administration in England was significantly restructured in 2006.
On 1 July 2006 the number of Strategic Health Authorities (SHAs) reduced from 28 to 10.
The boundaries of the new SHAs are coterminous with Government Office Regions (GORs), with the exception of the South East GOR which comprises two SHAs (which are constituted from groups of local authorities).
SHAs continue to report to the Department of Health.
On 1 October 2006 the number of Primary Care Organisations (PCOs) reduced from 303 to 152.
The PCOs are made up of 148 Primary Care Trusts and 4 Care Trusts.
The majority of the new PCOs are defined in terms of local authority districts.
Of the 152 PCOs:
130 comprise one or more whole local authority districts
16 comprise one or more whole local authority districts plus whole wards
three comprise only whole wards within a single local authority district
two comprise one or more whole local authority districts and part wards (that is, whole parishes)
one comprises whole and part wards (that is, whole parishes) within a single local authority district
PCOs report to the SHAs.
July 2003 to June 2006
The structure for health administration in England came into effect on 1 July 2003.
There were 28 Strategic Health Authorities (SHAs), which were constituted from groups of local authorities and performance managed the Primary Care Organisations (PCOs).
As of 1 October 2005 there were 303 PCOs including 299 Primary Care Trusts (PCTs) and four Care Trusts (CTs) based on the PCT model (this meant that they fulfilled all PCT functions and also delivered the health services usually provided by local authorities).
The PCOs were (mostly) aligned with the administrative boundaries existing at the time of the last major health reorganisation on 1 May 2002.
April 2002 to June 2003
During this period the Directorates of Health and Social Care (DHSCs) formed an additional top layer to the present structure.
There were four DHSCs, each covering one or more Government Office Regions (GORs).
DHSCs were part of the Department of Health rather than the NHS.
April 1999 to March 2002
A major reorganisation of English health geography occurred on 1 April 2002.
Before this there were eight Regional Offices (ROs), which were part of the Department of Health.
These were divided into approximately 100 Health Authorities (HAs), which in turn were split into PCOs.
When PCOs were first established in 1999 there were 481 Primary Care Groups (PCGs) but by 2002 a significant number had converted to PCTs.
The numbers of both HAs and PCOs varied slightly through this period.
Health geography before April 1999
The RO/HA structure shown (but without the PCOs) was introduced in April 1996.
Before this a structure of Regional and District Health Authorities (RHAs and DHAs) had been in place since 1982.