Discussion of the basic requirements for listing patents in the Orange Book and their interplay with 35 U.S.C. § 271(e), which is commonly the basis for lawsuits alleging infringement of listed patents. Consideration of recent cases that highlight some of the potential issues surrounding listing decisions, including the multiple Federal Circuit decisions Glaxo v. Teva and the Second Circuit’s recent decision in UFCW Local 1776 v. Takeda regarding the potential antitrust consequences of improperly listing patents in the Orange Book. Practical guidance that branded and generic companies should consider in building and assessing listed patent portfolios and developing litigation strategies.