Although there has been substantial work on argument-based approaches to validation as well as standard-setting methodologies, it might not always be clear how standard setting fits into argument-based validity. The purpose of this article is to address this lack in the literature, with a specific focus on topics related to argument-based approaches to validation in language assessment contexts. We first argue that standard setting is an essential part of test development and validation because of the important consequences cut scores might have for decision-making. We then present the Assessment Use Argument (AUA) framework and explain how evidence from standard setting can support claims about consequences, decisions, and interpretations. We finally identify several challenges in setting cut scores in relation to the levels of the Common European Framework of Reference (CEFR) and argue that despite these challenges, standard setting is a critical component of any claim focusing on the interpretation and use of test scores in relation to the CEFR levels. We conclude that standard setting should be an integral part of the validity argument supporting score use and interpretation and should not be treated as an isolated event between the completion of test development and the reporting of scores.