Objectives We describe a key informant study that invited national medicines policy leads for the European Union member states to self-assess the level of implementation of medicines adherence initiatives in their country and the adequacy of that implementation. Interviews with medicines policy leads enabled in-depth understanding of the variation in adherence support across nations and the ways in which different nations prioritize, plan, and implement medicines adherence systems and services. Methods Ten national policy leads (Bulgaria, Denmark, Estonia, Finland, Germany, Ireland, Latvia, Lithuania, Malta, and the Netherlands) completed a self-assessment survey, and seven (Estonia, Finland, Germany, Ireland, Lithuania, Malta, and the Netherlands) engaged in a follow-up interview. Key findings Policy leads varied in the level of implementation of medication adherence solutions that they reported in their nations; most initiatives were aimed directly at patients with few initiatives at government or health care commissioner levels of action. Policy leads reported insufficient implementation of medication adherence initiatives across all potential domains. Barriers to implementation included lack of resources, strategic planning, evidence to support action, the “hidden” nature of medication adherence within policy work, and dispersed responsibility for medication adherence as a policy and practice theme. Conclusion This study has international significance and summarizes the emergent characteristics of nations with and without coordinated medication adherence activity. We highlight the importance of sharing good practice in policy formulation and implementation for medication adherence.