This article examines the extent to which different groups of university students have shared vocabulary needs. Previous research in this area is limited in that it: (i) has focused on items from Coxhead's Academic Word List (2000), which is skewed towards certain disciplines, and focuses only on reading needs; (ii) has not investigated variation across levels of study; and (iii) creates a possibly false dichotomy between generic and discipline-specific vocabulary. The intermediate position--that broad groups of students may have similar vocabulary needs--is not considered. This article aims to further our understanding of variation in academic vocabulary by: (i) analysing the extent to which student writing across disciplines and levels of study draws on generic or specialized vocabulary, and (ii) identifying clusters of student groups with shared vocabulary needs. It finds substantial variation between disciplines, which is only slightly lessened when related disciplines are grouped together. Most disciplines are relatively internally homogeneous, and so good candidates for teaching units, though the vocabulary of masters students often diverges considerably from that of undergraduates.