The effective filing date of a claimed invention is a central concept relevant to several key provisions of the America Invents Act (AIA). It determines the universe of prior art available against a claim or application and also renders a claim or application eligible for the new first-inventor-to-file provisions. The effective filing date is the earlier of (1) the filing date of a patent or patent application including a claim to the invention, or (2) the filing date of the earliest priority application (i.e., the earliest filed provisional, nonprovisional, international, or foreign application) to which a patent or patent application is entitled to a right of priority for the claimed invention. In general, this means a claim is entitled to the filing date of the earliest filed application supporting that claim.

Under the AIA’s novelty requirement, an applicant cannot receive a patent if its claimed invention was described in a patent or printed publication, or was in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. An inventor, however, may rely on a one-year grace period, which disqualifies certain disclosures by the inventor as prior art to the inventor. The grace period is designed to ensure that the patentability of an invention is not defeated by an inventor’s own disclosures, disclosures of information obtained from the inventor, or third-party disclosures that include the inventor’s previous public disclosures. To qualify, the disclosure by the inventor or of the inventor’s work must have been made one year or less before the effective filing date of a claimed invention. The effective filing date is also central to the first-inventor-to-file provisions of the AIA, which prohibit an applicant from receiving a patent if its claimed invention was described in a patent or a published application naming another inventor filed before the filing date of the application containing the claimed invention. This rule applies to any patent or patent application that contains, or contained at any time, a claim to an invention having an effective filing date on or after March 16, 2013. Any application that claims priority to such an application also falls under the first-inventor-to-file provisions.

As this overview demonstrates, before accurately applying the new AIA rules, one must first determine the effective filing date of a claim.