Opinions have been divided regarding the relevance of the APA Ethics Code to non-mental health specialties and even whether the code should attempt to encompass all psychology specializations. However, these opinions have crystallized without the benefit of any appreciable empirical data, until now. This study investigates the applicability of the ethical principles and standards of the code to 398 first-person narratives of ethical incidents reported by industrial-organizational (I-O) psychologists. On average, 2.8 (of the 5) principles enumerated in the code were deemed applicable to each incident, and each principle was applicable to more than half the incidents provided. Of the code’s 89 ethical standards, 75 (84.3%) were applicable to at least one incident. Among the 10 categories of standards, resolving ethical issues and human relations were the most frequently applicable, whereas therapy standards were virtually never applicable. However, for 42.7% of the incidents, trained judges identified a substantive deficiency or ambiguity for I-O psychologists in the code. These deficiencies were subsequently grouped into seven higher order categories (assessments in organizations; research practices; data management; professional interactions; business practices; student ethics; and proactive ethical behavior). Recommendations are offered for improving those putative deficiencies, and implications are discussed for I-O psychologists, the APA’s Ethics Code Task Force (ECTF), and other nonclinical domains of psychology.