This chapter advances the claim that judges have an ethical obligation of competence that requires them to enhance their knowledge about language (in the context of statutory interpretation) and income tax law design and policy. It articulates some of the foundational understandings that support that competence and provides a simple hierarchy of approaches to interpreting income tax law. It concludes by contending that greater competence is not only more ethical but also advances other important societal goals fulfilled by the imposition of income tax systems.