In May 2016, Government funding of £80 million was awarded to establish five employer-led National Colleges in key growth sectors -- Creative and Cultural (NCCI), Digital Skills (Ada), Nuclear (NCfN), High Speed Rail (NCHSR) and Oil and Gas. This was alongside substantial investment from Local Authorities (LAs), Local Enterprise Partnerships (LEPs), industry bodies and businesses. The Colleges opened between 2016 and 2018 (Ada and NCCI in 2016, NCHSR in 2017 and NCfN in 2018). At the end-point of the initial phase of delivery, in December 2018, the Department for Education (DfE) commissioned the Institute for Employment Studies (IES) to carry out a process evaluation. Its aims were to: (1) Explore the implementation and delivery of National Colleges to date from the perspectives of key stakeholders; (2) Identify factors that have helped or hindered effective implementation of National College policy; and (3) Identify lessons learned about how delivery can be improved or refined, and more broadly, applied across DfE's programmes, particularly the Institutes of Technology. The research was primarily qualitative in nature and took place from February-April 2019. It involved an initial scoping phase, which incorporated a review of National College policy documentation as well as the original and revised business plans of the four National Colleges that had opened at this time. This provided further detail on how the policy had been implemented by government as well as the National Colleges' delivery plans and how these had evolved over time. This phase of research was followed by in-depth case studies of each of the four National Colleges. The case studies incorporated day visits to the different National College campuses to interview staff and conduct focus groups with learners. Telephone interviews with other stakeholders engaged in delivery were also completed, including employers, National College board members, sector/trade bodies, and representatives of LAs and LEPs that provided co-funding.