This report sets outs out the findings from a Realistic Medicine Evaluability Assessment that took place between January and March 2019. Evaluability Assessment is a systematic and collaborative approach to planning evaluation based on structured engagement around intervention goals, and evaluation priorities and options. Three workshops were held involving a mix of policy, clinical and research interests which reviewed and discussed the Realistic Medicine driver diagram; priorities for measurement and evaluation; data sources and evaluation design. The report sets out a series of options and recommends a mixed methods approach to evaluation that aims that make best use of existing data supplemented by new primary data gathering to fill the most important gaps.