What is the difference between handling prior art citations in ex parte and inter partes reexaminations?

While there are similarities in handling prior art citations between ex parte and inter partes reexaminations, there are also key differences. According to MPEP 2602:

“If the prior art citation satisfies 37 CFR 1.501 and was submitted prior to an order for reexamination, the cited documents (citations) will be considered in an inter partes reexamination proceeding as a prior art citation would be considered in an ex parte reexamination proceeding.”

However, the main differences include:

• In inter partes reexamination, third party requesters can submit prior art citations as part of their comments during the proceeding (37 CFR 1.947 or 1.951(b)).
• Citations submitted after an order for inter partes reexamination by persons other than the patent owner or third party requester are delayed in entry until the reexamination concludes.
• Ex parte reexamination allows for more flexible submission of prior art by third parties throughout the proceeding.

For specific handling of prior art citations in ex parte reexamination, MPEP 2602 refers to MPEP § 1502.

To learn more:

• ex parte reexamination
• inter partes reexamination
• prior art citations
• USPTO procedure