Much current work in management of innovation argues that it is becoming increasingly necessary for inventors and their firms to exploit information and capabilities outside the firm in order to combine one’s own resources with resources from the external environment. Building on this prior work, we examine the relationship between collaboration and innovation. Using detailed information on a sample of triadic patents, with over 1900 responses in the US, we report on the rates of collaboration of various forms, and test the effects of collaboration. Our results suggest that just over 10% of inventions involve an external co-inventor and about 23% involve external (non-co-inventor) collaborators (with 27% involving any external collaborators). We find evidence that heterogeneous collaboration and university-industry collaboration in inventing drive higher invention quality. However, vertical collaboration at the inventing stage is relatively more critical to commercialization at the implementation stage than is university-industry collaboration. These results suggest that the impact of different forms of collaborative innovation may vary depending on the stage of the innovation process.