The aim of this study is to define epigenetic literacy and describe how it can be included in school biology. Epigenetics is a new field of research in biology with abundant societal consequences and conceptual implications on how genetics is understood. Epigenetics explains how genes are regulated, thereby clarifying cell differentiation, and providing an understanding of how the environment interacts with genes. Students are bound to encounter epigenetic knowledge and applications related to issues such as health, food, and exercise in the media and their everyday lives. Consequently, there is a need to develop epigenetic literacy. Nevertheless, epigenetics is missing in biology curricula and is almost unknown among teachers and students. Research on epigenetics in science education is scarce, and we do not know what and how to teach. Therefore, we conducted a policy Delphi study with a panel of experts to define an epigenetic literacy framework for teaching in secondary education in relation to Robert's Vision I and Vision II perspectives on epigenetic literacy. Participants were 41 recognized international experts representing 11 countries and five areas of expertise. The experts suggested that epigenetics should be introduced in the lower secondary genetics course (students aged 13-15 years), but also addressed in other relevant areas of biology. The study generated six content themes: "epigenetics as a metaphor"; "epigenetics connecting nature with nurture"; "epigenetics as a dynamic process"; "epigenetic mechanisms"; "epigenetics and inheritance"; and "epigenetics and nature of science," and five sociocultural themes for contextualization: "epigenetics and lifestyle"; "epigenetics and diseases"; "epigenetics and ethics"; "epigenetics and policies"; and "epigenetics and forensics." Taken together, these themes constitute the epigenetic literacy framework. Further, we uncover divergent meanings in the expert panel--as is typical of policy Delphi studies--and connect the framework to genetic literacy and learning progressions in genetics education.