When criminal liability is at stake, the Chevron doctrine of judicial deference to reasonable agency interpretations of ambiguous regulatory statutes is said to conflict with the doctrine of lenity, which requires strict construction of ambiguous criminal statutes. This paper argues, however, that courts should reject a criminal liability exception to Chevron. Chevron is consistent with administrative law doctrines that realistically recognize that Congress and agencies together define administrative crimes, while lenity rhetoric contends that only Congress can create federal crimes. Chevron principles should promote important values of national uniformity, policy coherence, and equal treatment. In contrast, the criminal liability exception could lead to different interpretations of a provision in civil as opposed to criminal contexts or could undermine agency authority in non-criminal contexts if a narrow construction were applied in a facial challenge to a provision that could trigger criminal sanctions in another case. Moreover, lenity's core value, fair warning, can also be protected under Chevron when agency regulations or other administrative constructions clarify ambiguous statutory provisions prior to criminal conduct. Finally, the paper argues that the criminal liability exception could be difficult to administer because there is no bright line between criminal and civil sanctions.