From proficiency to preparedness

English language proficiency has become the default explanation for participation and success in EMI. While proficiency clearly matters, its explanatory dominance has narrowed how participation in EMI is understood. Students who meet institutional language thresholds continue to encounter difficulties with assessment expectations, disciplinary writing, classroom interaction, and epistemic conventions, raising a simple question. What, exactly, are proficiency measures assumed to explain? Building on arguments first advanced in a recent TESOL Journal article and subsequent scholarly dialogue, this paper develops preparedness as an analytic reframing of EMI participation. Preparedness is proposed as a redirection of attention from individual linguistic deficit toward alignment with disciplinary practices, curricular structures, and assessment expectations. Framed in this way, recurring EMI challenges appear less as evidence of insufficient language ability and more as signals of misalignment between learners and the academic environments they enter. This paper clarifies the conceptual boundaries of preparedness, addresses concerns about normative academic expectations across contexts, and considers implications for assessment beyond gatekeeping models. It argues that moving from proficiency to preparedness allows EMI research to shift from asking how much English is enough toward examining how participation in disciplinary knowledge practices becomes learnable.