In 2002 the health authorities were reorganised and their boundaries changed to constitute 28 strategic health authorities, which were reduced in number to 10 in 2006.
Prior to 1996 the service was organised according to regional health authorities.
These Health Authorities were established in 1996. There were a few changes between then and the final form shown above. There were originally separate authorities for Barnet and Enfield & Haringey, for Bexley & Greenwich and Bromley, for East & North Hertfordshire and South Hertfordshire, and for the Isle of Wight & Portsmouth and South-East Hampshire.  Also, the area of Norfolk and Cambridgeshire was partitioned between three authorities : Cambridge & Huntingdon, East Norfolk, and North West Anglia. North West Anglia included from Cambridgeshire: Peterborough, Fenland, part of Huntingdonshire, and from Norfolk: King's Lynn and West Norfolk and part of Breckland.