This paper provides a definition of "cadential function" general enough for serial and atonal music, and applies it to the analysis of Schoenberg's Op. 25 and Op. 11/1. Theorists typically distinguish sections within Schoenberg's music via row manipulations or set-class relationships, however this does not explain how a single phrase projects beginnings, middles, and ends. Literature on the cadence tends to focus on tonal musical styles and rely on triadic harmonic progressions. For instance, Caplin only recognizes a cadence in the Classical style when cadential content (V-I) arrives at the end of a phrase. On the other hand, Nobile assumes that the tonic chord is self-evident in rock music and explains the cadence through a more flexible harmonic syntax. I will show that the Menuet and Musette from Schoenberg's Suite for Piano Op. 25 expresses tight-knit theme-types and that cadences occur in their expected locations in the phrase. My underlying formal functions are hybrids of the ones presented in Schoenberg's Fundamentals of Musical Composition and Caplin's Classical Form, as well as more recent scholarship on Romantic theme-types. Furthermore, the Op. 25 cadences match Schoenberg's rhetorical descriptions of "cadence contour" marking them as "ends" rather than "stops." Building on this initial concept for serial cadence, I compare these themes to their recapitulations in the movement's ternary formal schemes to compare the strength of their cadences. Finally, I will demonstrate how this concept of cadence can inform the analysis of Schoenberg's Op. 11/1, where normative theme-types are not present.