Using novel data from Kipsigis (Southern Nilotic; Kenya), we present the first attested case of across-the-board paradigmatic tonal polarity. The nominative case forms of nominal modifiers (adjectives, possessives, and demonstratives) are segmentally identical to their oblique case counterparts but have the opposite tonal pattern across-the-board: nominative and oblique modifiers differ in not just one but EVERY tonal specification. Kipsigis polarity thus results in maximal tonal contrast between two morphologically related words. We show how the Kipsigis pattern may be captured in an item-and-process theory of morphology with dedicated exchange mechanisms and an item-and-arrangement theory that allows for morpheme-specific phonology; we suggest that an item-and-process approach may provide a more straightforward account.