Introduction Complementary and alternative medicine (CAM), often accessed privately, can be integrated with conventional care. Little is known about current integration in the UK National Health Service (NHS). We provide an overview of integrated CAM services accessed from UK primary care for musculoskeletal and mental health conditions, to identify key features and barriers and facilitators to integration. Methods Descriptive analysis of integrated services accessed from primary care providing CAM alongside conventional NHS care for musculoskeletal and/or mental health problems. A purposive sample was identified through personal contacts, social media, literature/internet searches, conferences, and patient/professional organisations. Questionnaires, documentary analysis and stakeholder meetings collected data on the service's history, features, integration, success and sustainability. Data was tabulated. Results From 38 sites identified, twenty sites were selected. Acupuncture and homeopathy were most common, followed by massage, osteopathy and mindfulness. GPs were often instrumental initiating services. NHS staff enthusiasm facilitated integration, as did an NHS setting, patient/public support, and being adjunctive to an NHS service. The main barriers to integration were funding, negative perceptions of CAM from the clinicians, funders and lobby groups, and local NHS staff attitudes/lack of knowledge. Reduced funding was often why services closed. Conclusions Various models for integrating CAM with UK primary care were identified. Social prescribing and NHS/patient co-funded CAM may be potentially sustainable models for future integration. Lack of funding and negative perceptions of CAM remain the primary challenge to integration. Evaluating effectiveness and cost-effectiveness of integrated services is vital to ensure sustainability.