Market Exclusivity Length for Drugs with New Generic or Biosimilar Competition, 2012–2018

Brand‐name drugs have periods of market exclusivity before generic competition begins. Due to high brand‐name drug prices charged during this period, market exclusivity is an important determinant of US prescription drug spending. We used claims data to estimate the market exclusivity period for 264 small molecule and 4 biologic drugs that faced new generic or biosimilar competition from 2012–2018. Exclusivity periods were longer for biologics...