We argue that the inflationary measure problem and the quantum Born rule share a common structural origin. Within Modal Triplet Theory, both are shown to arise as projections of a single basin–measure functional defined on an admissible coherent sector. We construct admissibility-weighted distributions over inflationary histories that are normalizable without ad hoc cutoffs and suppress runaway eternal inflation. The framework explains observed flatness and connects cosmological probability measures to quantum measurement as distinct shadows of the same underlying structure.