14 May 2020: Four new ICS announced.
Hertfordshire and West Essex
Humber, Coast and Vale
South West London
All four were previously sustainability and transformation partnerships, with Sussex and East Surrey STP becoming Sussex ICS. East Surrey has joined the Surrey health system.
It is NHS England's intention that all STP areas are fully functioning Integrated Care systems (formerly called Accountable Care Systems) known as ICS, with powers transferred from NHS England even though they are not statutory bodies, by 2021.