Provisional Patent Application Priority and the Importance of Determining Effective Filing Dates

The recent precedential Federal Circuit decision on March 24, 2025 in In re Riggs, Case No. 2022-1945 (Fed. Cir. Mar. 24, 2025) is a reminder to patent practitioners and examiners, alike, of the importance of provisional support for subsequently filed applications that claim priority to the provisional.   

Essentially, the Riggs decision aligns with the MPEP with respect to whether an Examiner’s reliance upon the provisional priority date of a published U.S. application can provide the basis for a prior art rejection. The MPEP provides that “[t]he provisional application must …