This Practice Note discusses procedural and strategic considerations involved in appealing final written decisions of the Patent Trial and Appeal Board (PTAB) in inter partes review (IPR), post-grant review (PGR), and covered business method (CBM) patentability challenges under the Leahy-Smith America Invents Act (AIA). It discusses grounds, timelines, and practical considerations for requesting rehearing of a final written decision before the PTAB and appeal to the US Court of Appeals for the Federal Circuit.