This chapter focuses on the different forms of television adaptation, and examines the ramifications of television structures on our understanding of the process of adaptation, as well as adaptation's influence on television storytelling. It begins by analyzing a genre that has only rarely been examined as adaptation, the television sitcom, so as to examine the changing implications of just what is adaptable when moving from a finite to an infinite model. The first and best-known of these is the short-form adaptation, which generally adapts over a limited run of episodes, and which has been characterized by their relative fidelity to their sources. The second form of television adaptation is perhaps less visible as adaptation; the long-form television adaptations take their inspiration from their source texts, but the episodic storytelling typical of television until the 1990s made the evolution inherent in the source text impossible, and the shows soon adapted the premise rather than the storyline of the original.