[1][2] Unlike other types of trust, they operate nationally rather than serve a specific geographical area.
They are a type of "Non-Administratively Classified Government Entities" of the Department of Health of the United Kingdom.
[3] Special health authorities are independent, but can be subject to ministerial direction like other NHS bodies.
[4][5][6] Prior to the repeal of the whole of the 1977 Act by the NHS (Consequential Provisions) Act 2006, special health authorities included both infrastructure support organisations and national/specialist treatment providers such as the Special Hospitals Service Authority and the Bethlem Royal and Maudsley Special Health Authority.
These direct clinical service providers were progressively merged with local NHS trusts and consequently with mainstream governance and funding arrangements.