MPEP § 2121 — Prior Art; General Level of Operability Required to Make a Prima Facie Case (Annotated Rules)

§2121 Prior Art; General Level of Operability Required to Make a Prima Facie Case

USPTO MPEP version: BlueIron's Update: 2026-01-10

This page consolidates and annotates all enforceable requirements under MPEP § 2121, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Prior Art; General Level of Operability Required to Make a Prima Facie Case

This section addresses Prior Art; General Level of Operability Required to Make a Prima Facie Case. Primary authority: 35 U.S.C. 132, 35 U.S.C. 102, and 37 CFR 132. Contains: 1 requirement, 1 permission, and 5 other statements.

Key Rules

Topic

Anticipation/Novelty

4 rules
StatutoryInformativeAlways
[mpep-2121-fc5ce982b80d2a6c3e790a52]
Examiner Can Reject Claims Based on Anticipation Without Enabling Inquiry
Note:
An examiner can reject patent claims as anticipated by prior art without verifying if the reference is enabling, provided they make a proper prima facie case and give adequate notice.

“Consistent with the statutory framework and our precedent, we therefore hold that, during patent prosecution, an examiner is entitled to reject claims as anticipated by a prior art publication or patent without conducting an inquiry into whether or not that prior art reference is enabling. As long as an examiner makes a proper prima facie case of anticipation by giving adequate notice under § 132, the burden shifts to the applicant to submit rebuttal evidence of nonenablement.”

Jump to MPEP Source · 37 CFR 132Anticipation/NoveltyPrinted Publication as Prior Art (MPEP 2128)Prior Art
StatutoryInformativeAlways
[mpep-2121-1c5a14828ea2fed19f269777]
Examiner's Prima Facie Anticipation Case Requires Applicant Rebuttal
Note:
If an examiner makes a proper prima facie case of anticipation by providing adequate notice under §132, the burden shifts to the applicant to submit evidence showing nonenablement.

“Consistent with the statutory framework and our precedent, we therefore hold that, during patent prosecution, an examiner is entitled to reject claims as anticipated by a prior art publication or patent without conducting an inquiry into whether or not that prior art reference is enabling. As long as an examiner makes a proper prima facie case of anticipation by giving adequate notice under § 132, the burden shifts to the applicant to submit rebuttal evidence of nonenablement.”

Jump to MPEP Source · 37 CFR 132Anticipation/NoveltyPrinted Publication as Prior Art (MPEP 2128)Prior Art
StatutoryRequiredAlways
[mpep-2121-125499402f0d58767a56f220]
Enabling Disclosure Requirement for Anticipation
Note:
A prior art reference must describe the claimed invention in sufficient detail to enable a person of ordinary skill to carry out the invention, without requiring proof of efficacy.

A prior art reference provides an enabling disclosure and thus anticipates a claimed invention if the reference describes the claimed invention in sufficient detail to enable a person of ordinary skill in the art to carry out the claimed invention; “proof of efficacy is not required for a prior art reference to be enabling for purposes of anticipation.” Impax Labs. Inc. v. Aventis Pharm. Inc., 468 F.3d 1366, 1383, 81 USPQ2d 1001, 1013 (Fed. Cir. 2006) (citing Rasmusson v. SmithKline Beecham Corp., 413 F.3d 1318, 1326, 75 USPQ2d 1297, 1302 (Fed. Cir. 2005)). See also MPEP § 2122.

Jump to MPEP SourceAnticipation/NoveltyPrior Art
StatutoryInformativeAlways
[mpep-2121-2bca6c3b4ae2a1757815ddb3]
Prior Art Must Enable Invention for Anticipation
Note:
A prior art reference must provide sufficient detail to enable a person of ordinary skill in the art to carry out the claimed invention for it to anticipate the claim.

A prior art reference provides an enabling disclosure and thus anticipates a claimed invention if the reference describes the claimed invention in sufficient detail to enable a person of ordinary skill in the art to carry out the claimed invention; “proof of efficacy is not required for a prior art reference to be enabling for purposes of anticipation.” Impax Labs. Inc. v. Aventis Pharm. Inc., 468 F.3d 1366, 1383, 81 USPQ2d 1001, 1013 (Fed. Cir. 2006) (citing Rasmusson v. SmithKline Beecham Corp., 413 F.3d 1318, 1326, 75 USPQ2d 1297, 1302 (Fed. Cir. 2005)). See also MPEP § 2122.

Jump to MPEP SourceAnticipation/NoveltyPrior Art
Topic

Types of Foreign Patents

2 rules
StatutoryRequiredAlways
[mpep-2121-0142e866621618db84c6185f]
Same Disclosure Required for All Prior Art Types
Note:
The level of disclosure needed to establish an enabling reference is uniform regardless of whether the prior art is a U.S. patent, foreign patent, printed publication, or any other type.

The level of disclosure required within a reference to make it an “enabling disclosure” is the same no matter what type of prior art is at issue. It does not matter whether the prior art reference is a U.S. patent, foreign patent, a printed publication or other. There is no basis in the statute (35 U.S.C. 102 or 103) for discriminating either in favor of or against prior art references on the basis of nationality. In re Moreton, 288 F.2d 708, 129 USPQ 227 (CCPA 1961).

Jump to MPEP SourceTypes of Foreign PatentsForeign Patent DocumentsPrior Art Sources
StatutoryInformativeAlways
[mpep-2121-92fc42ab03e01467c7d35a72]
No Discrimination Based on Nationality of Prior Art
Note:
The statute does not allow for favoring or disfavoring prior art references based on their nationality in determining operability for a prima facie case.

The level of disclosure required within a reference to make it an “enabling disclosure” is the same no matter what type of prior art is at issue. It does not matter whether the prior art reference is a U.S. patent, foreign patent, a printed publication or other. There is no basis in the statute (35 U.S.C. 102 or 103) for discriminating either in favor of or against prior art references on the basis of nationality. In re Moreton, 288 F.2d 708, 129 USPQ 227 (CCPA 1961).

Jump to MPEP SourceTypes of Foreign PatentsForeign Patent DocumentsPrior Art Sources
Topic

Prior Art

1 rules
StatutoryPermittedAlways
[mpep-2121-4feb638026f82165312d3166]
Applicant Can Argue Lack of Enablement Without Evidence
Note:
An applicant can challenge prior art as not enabling based on argument alone if it appears non-enabling on its face.

Where a reference appears to not be enabling on its face, however, an applicant may successfully challenge the cited prior art for lack of enablement by argument without supporting evidence. In re Morsa, 713 F.3d 104, 110, 106 USPQ2d 1327, 1332 (Fed. Cir. 2013).

Topic

35 U.S.C. 103 – Obviousness

1 rules
MPEP GuidanceInformativeAlways
[mpep-2121-f1443d37e4a18612a1ef9c12]
Reference Must Be Proven Inoperable to Overcome Anticipation
Note:
The reference that anticipates all elements of the claimed invention is presumed operable, and the burden shifts to the applicant to prove it inoperable.

When the reference relied on expressly anticipates or makes obvious all of the elements of the claimed invention, the reference is presumed to be operable. Once such a reference is found, the burden is on applicant to rebut the presumption of operability. In re Sasse, 629 F.2d 675, 207 USPQ 107 (CCPA 1980). See also MPEP § 716.07. See also In re Antor Media Corp., 689 F.3d 1282, 103 USPQ2d 1555 (Fed. Cir. 2012). Specifically, in In re Antor Media Corp., the court stated:

Jump to MPEP SourceObviousnessEstablishing Prima Facie CasePrima Facie Case of Obviousness
Topic

Rebutting Prima Facie Case

1 rules
MPEP GuidanceInformativeAlways
[mpep-2121-9efafe72a2c33b0f94592b83]
Burden to Rebut Presumed Operability of Anticipating Reference
Note:
Applicant must rebut the presumption that an anticipating reference is operable when it meets all claim elements.

When the reference relied on expressly anticipates or makes obvious all of the elements of the claimed invention, the reference is presumed to be operable. Once such a reference is found, the burden is on applicant to rebut the presumption of operability. In re Sasse, 629 F.2d 675, 207 USPQ 107 (CCPA 1980). See also MPEP § 716.07. See also In re Antor Media Corp., 689 F.3d 1282, 103 USPQ2d 1555 (Fed. Cir. 2012). Specifically, in In re Antor Media Corp., the court stated:

Jump to MPEP SourceRebutting Prima Facie CaseEstablishing Prima Facie CasePrima Facie Case of Obviousness
Topic

Establishing Prima Facie Case

1 rules
MPEP GuidanceInformativeAlways
[mpep-2121-d107d5465895de9c7e780fa2]
Operability Presumption for Anticipatory Prior Art
Note:
When a prior art reference anticipates all elements of an invention, it is presumed operable. The burden is on the applicant to prove otherwise.

When the reference relied on expressly anticipates or makes obvious all of the elements of the claimed invention, the reference is presumed to be operable. Once such a reference is found, the burden is on applicant to rebut the presumption of operability. In re Sasse, 629 F.2d 675, 207 USPQ 107 (CCPA 1980). See also MPEP § 716.07. See also In re Antor Media Corp., 689 F.3d 1282, 103 USPQ2d 1555 (Fed. Cir. 2012). Specifically, in In re Antor Media Corp., the court stated:

Jump to MPEP SourceEstablishing Prima Facie CasePrima Facie Case of ObviousnessRebutting Prima Facie Case

Citations

Primary topicCitation
Types of Foreign Patents35 U.S.C. § 102
Anticipation/Novelty35 U.S.C. § 132
Anticipation/NoveltyMPEP § 2122
35 U.S.C. 103 – Obviousness
Establishing Prima Facie Case
Rebutting Prima Facie Case
MPEP § 716.07
Types of Foreign PatentsIn re Moreton, 288 F.2d 708, 129 USPQ 227 (CCPA 1961)
Prior ArtIn re Morsa, 713 F.3d 104, 110, 106 USPQ2d 1327, 1332 (Fed. Cir. 2013)
35 U.S.C. 103 – Obviousness
Establishing Prima Facie Case
Rebutting Prima Facie Case
In re Sasse, 629 F.2d 675, 207 USPQ 107 (CCPA 1980)
Anticipation/Noveltyciting Rasmusson v. SmithKline Beecham Corp., 413 F.3d 1318, 1326, 75 USPQ2d 1297, 1302 (Fed. Cir. 2005)

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2026-01-10