1. The document presents a conceptual framework for pharmacoeconomic modeling of biosimilars in the US healthcare system. 2. Key challenges in modeling include price uncertainty, potential differences in indications from reference biologics, and uncertainty around interchangeability. 3. The framework recommends modeling a 35% average discount for biosimilars relative to reference biologics, biosimilar market share growth up to 60% over 10 years, and conducting sensitivity analyses to reflect uncertainty and the potential for factors and their interactions to change over time.