Aims and method The Maintaining Adherence Programme (MAP) is a new model of care for patients with schizophrenia, schizoaffective disorder and bipolar affective disorder which aims to encourage adherence and prevent relapse. This evaluation, conducted by retrospective and prospective data collection (including patient questionnaires and staff interviews), aimed to describe MAP's impact on healthcare resource use, clinical measures and patient and staff satisfaction, following its implementation in a university National Health Service (NHS) foundation trust in England. We included 143 consenting patients who entered MAP before 31 March 2012.Results In-patient bed days and non-MAP NHS costs reduced significantly in the 18 months post-MAP entry. At 15–18 months post-MAP, Medication Adherence Rating Scale scores had improved significantly from baseline and there was a shift towards less severe clinician-rated disease categories. Based on patient surveys, 96% would recommend MAP to friends, and staff were also overwhelmingly positive about the service.Clinical implications MAP was associated with reduced cost of treatment, improvements in clinical outcomes and very high patient and staff satisfaction.