This paper presents new analyses of four phonological processes in Kinande (Bantu, DRC)—Intonational Tone Assignment (ITA), Lexical Tone Assignment (LTA), Purposive Suffix Affixation (PSA), and Verbal Reduplication (VR)—and argues that they all crucially refer to a morphoprosodic "PStem" domain which, though derived from the morphosyntactic stem (the "MStem"), systematically excludes MStem-initial vowels (Downing 1999, 2000). The paper supports, therefore, the claim of Inkelas (1989) and Downing (1999) that phonological processes make reference to sub-lexical, non-metrical prosodic domains that are related to, but nevertheless distinct from, the domains of morphosyntax. At the same time, however, the paper argues against a crucial assumption made by Downing and Inkelas: namely that phonological processes can never make reference to morphosyntactic domains, but only to derived morphoprosodic ones. Since reference to the MStem as well as the PStem is demonstrated to be necessary to the full analyses of LTA and VR, the paper argues for a theory of the morphology-phonology interface in which phonological processes are permitted to refer both to morphoprosodic domains and the morphosyntactic constituents they are derived from.