As a result of the Wyeth v. Kappos decision
in early January 2010, the Patent Office changed the method it uses to calculate patent term adjustments. A patent term adjustment (PTA) adds extra time to a patent's term to compensate for prosecution delays that occurred because of the Patent Office. The new calculation method creates longer PTAs for most patents compared to the previous PTA calculation.
All patents currently being issued should use the new PTA calculation method. However, prior to about March 2, 2010, some PTAs may have been calculated using the older method. The Patent Office has provided a short, convenient form at http://www.uspto.gov/forms/sb0131.pdf
to request recalculation of the PTA. If you own a patent that issued prior to March 2 (and within the last six months), it only takes a few minutes to fill out the request for recalculation of the PTA and maybe gain some additional term for your patent.