The NHS Trust Development Authority (NHSTDA) was an executive non-departmental public body of the Department of Health. Its formation came as a result of reorganisation of the National Health Service (NHS) in England outlined in the Health and Social Care Act 2012. It is now part of NHS Improvement.
The NHSTDA existed to manage the process of NHS trusts becoming foundation trusts and to performance manage those hospital trusts that remained directly accountable to the NHS. In March 2014 it was reported there were 20 trusts which the TDA expected to end 2013-14 in the red. The Authority compiled a categorised list of NHS trusts, segmented into six broad groups, some of which were regarded as unlikely to have a future as independent organisations but refused to publish it.
It was announced in June 2015 that the chief executive posts at Monitor and the Authority were to be merged, although there would not be a complete merger of the organisations. Subsequently it was reported that the two organisations were to be completely merged. 
From 1 April 2016, the organisation is now part of NHS Improvement.
- "About". NHS Trust Development Authority. Retrieved 18 April 2013.
- "David Flory to step down as TDA chief executive". Health Service Journal. 4 March 2015. Retrieved 5 April 2015.
- "Move to block hospital closures law backed by 20 coalition MPs". The Guardian. 11 March 2014. Retrieved 16 March 2014.
- "'Trusts with no future' list on hold again". Health Service Journal. 5 October 2015. Retrieved 14 November 2015.
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- "KPMG wins £1m contract to design NHS Improvement". Health Service Journal. 27 October 2015. Retrieved 14 November 2015.