2710 Term Extensions or Adjustments for Delays Within the USPTO Under 35 U.S.C. 154 [R-2]
Utility and plant patents issuing on applications filed on or after June 8, 1995, but before May 29, 2000, are eligible for the patent term ** extension * provisions of former 35 U.S.C. 154(b) and 37 CFR 1.701. See MPEP § 2720. Utility and plant patents issuing on applications filed on or after May 29, 2000 are eligible for the patent term adjustment provisions of 35 U.S.C. 154(b)(amended, effective May 29, 2000) and 37 CFR 1.702-1.705. See MPEP § 2730.
Plant and utility patents issuing on applications filed before June 8, 1995 which have a term that is the greater of the “twenty-year term” (see MPEP § 2701) or seventeen years from patent grant are not eligible for term extension or adjustment due to delays in processing the patent application by the United States Patent and Trademark Office.
Since the term of a design patent is not affected by the length of time prosecution takes place, there are no patent term adjustment provisions for design patents.