Background: In Sweden, the National Guidelines for Substance Abuse Treatment includes new recommendations concerning integrating a user perspective. From 2009 to 2014, the Swedish National Board of Health and Welfare supported and financed the development of organizations serving regional users. The programme was evaluated, and the results showed a development of user influence in substance use treatment services in 20 out of 21 regions by 2014. The implementation of user organizations' influence was evaluated in 2018 for this follow-up study. Aim: The aim of this four-year follow-up study was to evaluate whether user organizations continued existing once national support ended, and whether their influence in social services and health care, at both organizational and individual levels had been implemented. Method: A questionnaire was dispatched to 20 regional user organizations. It included information and questions focused on their situation, and on participants' experiences of the influence of user organizations in health care and social service. Results: The results obtained from the questionnaire show that 14 out of 20 user organizations still existed and reported a developed influence in social services and health care at organizational and individual levels. National support was perceived as necessary for the ongoing development of user organizations and to continue increasing their influence. Conclusions: Support at the national level initiated the development of user influence in Sweden, which has increased at both organizational and individual levels in the context of social services, as well as in health care for persons with substance use disorders.