Glen is Chief Executive of the Foundation Group of Trusts which includes South Warwickshire University Foundation Trust, George Eliot Hospital NHS Trust ad Wye Valley NHS Trust. The Group was developed to support the Trusts as lead providers of integrated care in their localities. Glen joined the NHS as a Finance Trainee in 1983, becoming a Director of Finance in 1995 and then becoming Divisional Director at University Hospitals Coventry and Warwickshire in 1998.

In 2002 he was appointed as Deputy Chief Executive at Worcestershire Acute Hospitals NHS Trust and joined South Warwickshire in 2006. Since then the Trust has developed its local and national reputation, moving through financial turnaround, achieving Foundation Trust status in 2010, in 2011 completing the successful acquisition of Warwickshire Community Services and gaining Outstanding ratings for quality and use of resources in late 2019. Between 2015 and 2017 Glen was the National SRO for the Emergency Care Improvement Programme alongside his role in the Trust. The Foundation Group was created in 2018 where he is CEO of all Three Trusts as part of their innovative Group model.