MPEP § 2186 — Relationship to the Doctrine of Equivalents (Annotated Rules)

§2186 Relationship to the Doctrine of Equivalents

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 2186, 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.

Relationship to the Doctrine of Equivalents

This section addresses Relationship to the Doctrine of Equivalents. Primary authority: 35 U.S.C. 112(f) and 35 U.S.C. 112. Contains: 1 requirement, 1 guidance statement, and 1 other statement.

Key Rules

Topic

Required Claim Content

1 rules
StatutoryRequiredAlways
[mpep-2186-91fd32f4e7883f66206b2c4a]
Means-Plus-Function Claims Must Be Equivalent to Specified Means
Note:
Claims using means-plus-function limitations must be interpreted as covering only elements equivalent to those described in the patent specification.

35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, permit means- (or step-) plus-function limitations in claims to combinations, “with the proviso that application of the broad literal language of such claims must be limited to only those means that are ‘equivalent’ to the actual means shown in the patent specification. This is an application of the doctrine of equivalents in a restrictive role, narrowing the application of broad literal claim elements.” 520 U.S. at 28, 41 USPQ2d at 1870. Accordingly, decisions involving the doctrine of equivalents should be considered, but should not unduly influence a determination under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, during ex parte examination. See MPEP § 2183.

Jump to MPEP SourceRequired Claim ContentEquivalents Under 112(f) (MPEP 2185)
Topic

112(f) Indefiniteness (MPEP 2186)

1 rules
StatutoryInformativeAlways
[mpep-2186-81fe354cf41fa48e838bb4c7]
Means-Plus-Function Claims Must Be Equivalent to Specified Means
Note:
Claims using means-plus-function must be limited to means equivalent to those shown in the patent specification.

35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, permit means- (or step-) plus-function limitations in claims to combinations, “with the proviso that application of the broad literal language of such claims must be limited to only those means that are ‘equivalent’ to the actual means shown in the patent specification. This is an application of the doctrine of equivalents in a restrictive role, narrowing the application of broad literal claim elements.” 520 U.S. at 28, 41 USPQ2d at 1870. Accordingly, decisions involving the doctrine of equivalents should be considered, but should not unduly influence a determination under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, during ex parte examination. See MPEP § 2183.

Jump to MPEP Source112(f) Indefiniteness (MPEP 2186)35 U.S.C. 112(f) – Means-Plus-Function (MPEP 2181-2186)Required Claim Content
Topic

Equivalents Under 112(f) (MPEP 2185)

1 rules
StatutoryRecommendedAlways
[mpep-2186-98b6d0995b6605c69571dbdf]
Equivalents Not to Influence Means-Plus-Function Determination
Note:
During ex parte examination, decisions involving the doctrine of equivalents should be considered but must not unduly influence the determination under means-plus-function claim limitations.

35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, permit means- (or step-) plus-function limitations in claims to combinations, “with the proviso that application of the broad literal language of such claims must be limited to only those means that are ‘equivalent’ to the actual means shown in the patent specification. This is an application of the doctrine of equivalents in a restrictive role, narrowing the application of broad literal claim elements.” 520 U.S. at 28, 41 USPQ2d at 1870. Accordingly, decisions involving the doctrine of equivalents should be considered, but should not unduly influence a determination under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, during ex parte examination. See MPEP § 2183.

Jump to MPEP SourceEquivalents Under 112(f) (MPEP 2185)35 U.S.C. 112(f) – Means-Plus-Function (MPEP 2181-2186)Disclosure Requirements

Citations

Primary topicCitation
112(f) Indefiniteness (MPEP 2186)
Equivalents Under 112(f) (MPEP 2185)
Required Claim Content
35 U.S.C. § 112
112(f) Indefiniteness (MPEP 2186)
Equivalents Under 112(f) (MPEP 2185)
Required Claim Content
35 U.S.C. § 112(f)
112(f) Indefiniteness (MPEP 2186)
Equivalents Under 112(f) (MPEP 2185)
Required Claim Content
MPEP § 2183
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 40, 41 USPQ2d 1865, 1875 (1997)

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: 2025-12-31