There are many studies on supplier collaborations in NPD. However, there is not much written about what suppliers actually contribute to innovation. Based on a literature review focusing on 80 articles we develop a conceptual framework categorizing different supplier inputs to innovation. This model is formulated by characterizing supplier inputs related to the component level and architectural level, and inputs that are incremental or radical in nature. On a component level, supplier inputs can include the definition of the solution or refinement of existing components. On an architectural level it is less likely that suppliers contribute with radical inputs, but suppliers may assist NPD by refining architectural concepts.