Supplemental Examination

April 21, 2021

Supplemental examination may be requested by a patent owner in order to have the US Patent and Trademark Office (USPTO) consider, reconsider, or correct information that the patent owner believes is relevant to the patent. Generally, a supplemental examination can be used to help mitigate concerns of potential inequitable conduct during prosecution before the USPTO. In particular, per 35 U.S.C. § 257(c), a “patent shall not be held unenforceable on the basis of conduct relating to information that had not been considered, was inadequately considered, or was incorrect in a prior examination of the patent if the information was considered, reconsidered, or corrected during a supplemental examination of the patent.”

Supplemental examination is not limited to the consideration of patents and printed publications. Instead, a patent owner may request supplemental examination of its patent based on any of the following:

  • Patent eligible subject matter under Section 101
  • Anticipation under Section 102
  • Obviousness under Section 103
  • Public use or sale bars
  • Written description, indefiniteness, and enablement under Section 112
  • Double-patenting under Section 108

The standard for granting a supplemental examination request is whether one or more of the items presented by the patent owner (e.g., patents, printed publications, or other issues) raises a substantial question of patentability (SNQ). If the patent owner meets the requirements for a proper supplemental examination request, then the USPTO will conduct the supplemental examination within three months from when the proper supplemental examination request was made. The USPTO will ultimately conclude the supplemental examination by issuing a certificate indicating whether an SNQ has been raised.

When the USPTO determines that an SNQ has been raised, an ex parte reexamination will be ordered. Ex parte reexaminations that follow a supplemental examination are significant because they are not limited to patents and printed publications. Finally, the USPTO will issue an ex parte reexamination certificate after the ex parte reexamination is complete. This certificate will indicate whether the reexamined claims are cancelled, amended, newly added, or unchanged.