This article reports a case study of an undergraduate English-medium program at a major university in mainland China. The study critically examines the language ideology, language management, and language practices revolving around the focal program. The data sources included national and institutional policy documents related to English-medium instruction and interviews with both professors and students in the English-medium program and its parallel Chinese-medium program. Drawing upon Spolsky's language policy framework for "sensitizing concepts", qualitative analyses of the data revealed gaps between policy rhetoric and ground-level reality in the implementation of the focal program. Notably, institutional measures intended to enhance the quality of English-medium instruction were found to function as gate-keepers of access to English and potential benefits accruing from English proficiency. These findings add to our understanding of how medium-of-instruction policies in higher education are complicit in perpetuating and accentuating inequalities in Chinese society.