This article deals with a so-far unnoticed phenomenon in prosodic phonology, which we dub prosodic smothering. Prosodic smothering arises when the prosodic status of a clitic or affix varies with the presence or absence of some outer morpheme. We first illustrate prosodic smothering with novel data from two genetically unrelated languages, Macedonian (Slavic) and Kaqchikel (Mayan). We then provide a unified account of prosodic smothering based on a principled extension of the theory of prosodic subcategorization (e.g., Inkelas 1990, Peperkamp 1997, Chung 2003, Yu 2003, Paster 2006, Bye 2007). Prosodic subcategorization typically involves requirements placed on items to the left or the right of the selecting morpheme. We show that prosodic smothering naturally emerges in a theory that also allows for subcategorization in the vertical dimension, such that morphemes may select for the prosodic category that immediately dominates them in surface prosodic structure. This extension successfully reduces two apparent cases of nonlocal prosodic conditioning to the effects of strictly local prosodic selection.