35 U.S.C. · Part II · Chapter 10, Patentability of inventions

35 U.S.C. 102: Conditions for patentability; novelty

In plain English

Section 102 defines novelty and the prior art that can defeat it. Under section 102(a)(1), a claimed invention is not new if, before its effective filing date, it was patented, described in a printed publication, in public use, on sale or otherwise available to the public, anywhere in the world. Under section 102(a)(2), earlier-filed US patents and published US applications naming another inventor are prior art as of their effective filing date, which can be the date of a foreign priority application (section 102(d)).

Section 102(b) lists the exceptions. Under (b)(1), a disclosure made 1 year or less before the effective filing date is not prior art if it came from the inventor, or from someone who got the subject matter from the inventor, or if the inventor had already publicly disclosed the same subject matter before the third party did. Under (b)(2), earlier-filed patent documents are excluded if they were derived from the inventor, if the inventor publicly disclosed the subject matter first, or if they were commonly owned (or under an obligation of assignment to the same person) by the effective filing date. Section 102(c) treats parties to a written joint research agreement as common owners.

Anticipation under section 102 needs a single reference that discloses every element of the claim, arranged as claimed, either expressly or inherently (MPEP 2131). If it takes two references, or one reference plus common knowledge, the rejection belongs under section 103.

Annotation by Raj Sutariya, Co-founder, PatentAssist.ai. General information, not legal advice; the statute below governs.

AIA and pre-AIA

Pre-AIA section 102 still governs applications and patents whose claims all have effective filing dates before March 16, 2013. It was a first-to-invent system: prior art was measured from the date of invention under pre-AIA 102(a), the one-year statutory bars ran from the US filing date under 102(b), earlier-filed US applications were prior art from their US filing date under 102(e), and prior invention by another counted under 102(g). An applicant could antedate a reference with a 37 CFR 1.131 declaration of prior invention. None of that is available for AIA applications, where the effective filing date controls and only the 102(b) exceptions apply.

Text of 35 U.S.C. 102

Current text, quoted from the official United States Code.

(a) Novelty; Prior Art.— A person shall be entitled to a patent unless—
(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention; or
(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
(b) Exceptions.—
(1) Disclosures made 1 year or less before the effective filing date of the claimed invention.— A disclosure made 1 year or less before the effective filing date of a claimed invention shall not be prior art to the claimed invention under subsection (a)(1) if—
(A) the disclosure was made by the inventor or joint inventor or by another who obtained the subject matter disclosed directly or indirectly from the inventor or a joint inventor; or
(B) the subject matter disclosed had, before such disclosure, been publicly disclosed by the inventor or a joint inventor or another who obtained the subject matter disclosed directly or indirectly from the inventor or a joint inventor.
(2) Disclosures appearing in applications and patents.— A disclosure shall not be prior art to a claimed invention under subsection (a)(2) if—
(A) the subject matter disclosed was obtained directly or indirectly from the inventor or a joint inventor;
(B) the subject matter disclosed had, before such subject matter was effectively filed under subsection (a)(2), been publicly disclosed by the inventor or a joint inventor or another who obtained the subject matter disclosed directly or indirectly from the inventor or a joint inventor; or
(C) the subject matter disclosed and the claimed invention, not later than the effective filing date of the claimed invention, were owned by the same person or subject to an obligation of assignment to the same person.
(c) Common Ownership Under Joint Research Agreements.— Subject matter disclosed and a claimed invention shall be deemed to have been owned by the same person or subject to an obligation of assignment to the same person in applying the provisions of subsection (b)(2)(C) if—
(1) the subject matter disclosed was developed and the claimed invention was made by, or on behalf of, 1 or more parties to a joint research agreement that was in effect on or before the effective filing date of the claimed invention;
(2) the claimed invention was made as a result of activities undertaken within the scope of the joint research agreement; and
(3) the application for patent for the claimed invention discloses or is amended to disclose the names of the parties to the joint research agreement.
(d) Patents and Published Applications Effective as Prior Art.— For purposes of determining whether a patent or application for patent is prior art to a claimed invention under subsection (a)(2), such patent or application shall be considered to have been effectively filed, with respect to any subject matter described in the patent or application—
(1) if paragraph (2) does not apply, as of the actual filing date of the patent or the application for patent; or
(2) if the patent or application for patent is entitled to claim a right of priority under section 119, 365(a), 365(b), 386(a), or 386(b), or to claim the benefit of an earlier filing date under section 120, 121, 365(c), or 386(c), based upon 1 or more prior filed applications for patent, as of the filing date of the earliest such application that describes the subject matter.

Key cases

Pfaff v. Wells Elecs., Inc., 525 U.S. 55 (1998). The on-sale bar applies when, before the critical date, the invention was the subject of a commercial offer for sale and was ready for patenting, for example shown by drawings detailed enough to let a skilled person make it.
Helsinn Healthcare S.A. v. Teva Pharmaceuticals USA, Inc., 586 U.S. 123 (2019). The AIA did not change the meaning of “on sale”. A commercial sale to a third party who must keep the invention confidential can still put the invention on sale under section 102(a)(1).

Practical notes

Treat the grace period as a safety net, not a plan. It only covers the inventor's own disclosures and what flows from them, and the protection against intervening third-party disclosures under 102(b)(1)(B) is limited to the same subject matter the inventor disclosed. Europe and most other patent systems have no general grace period, so a disclosure that is harmless in the US can still destroy novelty abroad.

Watch commercial activity as closely as publications. After Helsinn, a confidential supply agreement or a signed purchase order can start the one-year clock. File before the first offer for sale, launch, pitch to a customer, conference talk or preprint; a provisional application is the cheap way to do that.

To invoke a 102(b) exception during examination, file a declaration under 37 CFR 1.130 showing that the disclosure was the inventor's own, or that the inventor's public disclosure came first. For commonly owned (b)(2)(C) art, a clear statement of common ownership in the reply is usually enough (MPEP 717).

Related rules and guidance

37 CFR: § 1.109, § 1.130, § 1.131, § 1.55, § 1.78
MPEP: 717, 2128, 2131, 2132, 2133, 2150, 2152, 2153, 2154, 2155, 2159