This paper introduces the Michigan Corpus of Upper-level Student Papers (MICUSP) as a new resource that will enable researchers and teachers of English for Academic Purposes (EAP) to investigate the written discourse of highly advanced student writers whose written assignments have been awarded the grade 'A'. The usefulness of two aspects of the design of the corpus — variation across discipline and across student level — is illustrated by two case studies, one on attribution and one on recurrent phraseological patterns. The first case study investigates how references to the work of others are realized and to what extent disciplinary variation exists in unpublished academic writing by students. The second study examines the use of phraseological items (n-grams and phrase-frames) by students at four different levels of undergraduate and graduate study. The paper closes with a discussion of the results of both case studies and describes future avenues for MICUSP-based research.