- Prejudgment Interest Is Awarded Absent Undue Delay By Patent Owner: Prejudgment interest is a form of compensatory damages, i.e., “actual damages.” Sanofi-Aventis (Fed. Cir. 10/18/11). Neither bad faith nor an exceptional case is required for a court to award prejudgment interest. General Motors (U.S. 05/24/1983) (“underlying purpose of the provision strongly suggests that prejudgment interest should ordinarily be awarded where necessary to afford the plaintiff full compensation for the infringement,” but “it may be appropriate to limit prejudgment interest, or perhaps even deny it altogether, where the patent owner has been responsible for undue delay in prosecuting the lawsuit”). Five-year delay in bringing suit after learning of infringement does not necessarily bar prejudgment interest. Kaufman (Fed. Cir. 05/20/22) (rev’g denial of prejudgment interest from 2011 date of hypothetical negotiation, based on lump sum payment in 2011, where no evidence that defendant would have altered its product had it been sued earlier). Court has wide discretion in determining the rate. Uniroyal (Fed. Cir. 07/10/91) (aff’g award of pre-judgment interest at prime rate, partly because litigation was protracted). Interest may be awarded on the entire damages amount from the date of first infringement where jury awarded lump-sum damages amount. Schwendimann (Fed. Cir. 05/13/20) (aff’g award of 10% (state statutory rate) prejudgment interest). May be different rate pre- and post-suit. Exmark II (Fed. Cir. 10/07/20) (non-precedential) (aff’g trial court adjusting prejudgment interest for pre-suit period only to account for delay bringing lawsuit).