This chapter surveys the key principles of the framework of Distributed Morphology (Halle & Marantz 1993, 1994). This summary distinguishes itself from other such summaries by focusing primarily on DM’s morphological properties rather than its syntactic ones. Thus it focuses on morphological concerns such as the morpheme-based hypothesis, realizational morphology, morphological rules, segmentability, derivation vs. inflection, underspecification, productivity, blocking, allomorphy, and the interfaces of morphology with syntax and phonology. This chapter emphasizes metatheoretical concerns that would be of interest to students of comparative morphological theory with a significant focus on the strengths and weaknesses of Distributed Morphology as a theory of morphology. Secondary focus is also given to internal metatheoretic debates such as the status of roots in the grammar and the power of post-syntactic rules.