What is the impact of genetics and genomics on issues of identity and what do we mean when we speak of identity? This paper explores how certain concepts of identity used in philosophy can be brought together in a multi-layered concept of identity. It discusses the concepts of numerical, qualitative, personal and genetic identity-over-time as well as rival concepts of genomic identity-over-time. These are all understood as layers in the multilayered concept of identity. Furthermore, the paper makes it clear that our understanding of genomic identity and the importance attached to genomic sameness-over-time matters for the ethical questions raised by certain new gene technologies.