How Long is the Rehearing Wait?
A Petition for Rehearing may be filed in an AIA Trial Proceeding to challenge an Institution Decisions (ID) or a Final Written Decision (FWD) of the Patent Trial & Appeal Board (PTAB). Of course, a successful Petition for Rehearing is a rare occurrence. Fewer than 5% of cases to date have seen a successful Petition for Rehearing.
A Petition for Rehearing pursued after an ID is often deemed to have the longest odds of success given the 314(d) bar to appealing such decisions (now pending review in WiFi One). On the other hand, given the ultimate appeal of FWDs to the Federal Circuit, it may be that such filings inherently enjoy closer scrutiny, and hence, slightly better odds of success.
In any event, both patentees and petitioners alike sometimes find it necessary to pursue rehearing for any number of strategic goals. But, given the lack of a mandated deadline for such decisions, the question becomes: “How Long is the Wait?”
ID Rehearing Pendency = 66 days

*Two proceedings (one of which a group of related proceedings) in this timeframe had pendencies over 300 days, if counted this would raise the average to 139 days. These delays appear to have been anomalies, and as such, are omitted.
Given the statutory deadline on open AIA trial proceedings, which would not apply to rehearing requests of FWDs (i.e., statutory clock stops at final written decision), these requests pend, on average a month longer than those rehearings pursued after ID. One downside to such pendencies after FWD is that a party may file rehearing for the sole purpose of securing delay of the appeal. Likewise, overall pendency of AIA trials to a final CAFC resolution will be correspondingly extended, providing fodder for PTAB critics.