Miller has been a non-executive director since the establishment of the integrated care board in July 2022.
He said: ‘I leave my role with a great sense of pride in what the ICB and the wider system has achieved over the last two years and believe that the best is yet to come for BSW.
‘My new role as chair of AWP enables me to continue to play an active role across BSW, and one that is focused on improving the mental health of our diverse population at every stage of their adult lives.'
Stephanie Elsy, BSW ICB Chair, added: ‘I am delighted that Paul will still be very much part of the health and care system, working to support some of the most vulnerable people within our communities.'
Miller will step down from his role at the ICB at the end of October to take up the role of chair at the mental health, learning disability and autism provider on 1 November.