Multiple authorship is becoming increasingly common in bioethics research. There are well-established criteria for authorship in empirical bioethics research but not for conceptual research. It is important to develop criteria for authorship in conceptual publications to prevent undeserved authorship and uphold standards of fairness and accountability. This article explores the issue of multiple authorship in bioethics and develops criteria for determining who should be an author on a conceptual publication in bioethics. Authorship in conceptual research should be based on contributing (...) substantially to: (1) identifying a topic, problem, or issue to study; (2) reviewing and interpreting the relevant literature; (3) formulating, analyzing, and evaluating arguments that support one or more theses; (4) responding to objections and counterarguments; and (5) drafting the manuscript and approving the final version. Authors of conceptual publications should participate substantially in at least two of areas (1)?(5). (shrink)