When first introduced 4 years ago, pharmacy directors were not convinced they would reap benefits from biosimilars. That lack of confidence has completely dissipated. The vast majority of hospital pharmacies have adopted the currently available biosimilar products, and most plan to add additional biosimilars to their formulary as they enter the market. While cost savings drives biosimilar adoptions, there is growing interest in interchangeability as this designation eases the switching process for pharmacy.