MPEP § 2182 — Search and Identification of the Prior Art (Annotated Rules)

§2182 Search and Identification of the Prior Art

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

This page consolidates and annotates all enforceable requirements under MPEP § 2182, 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.

Search and Identification of the Prior Art

This section addresses Search and Identification of the Prior Art. Primary authority: 35 U.S.C. 112. Contains: 2 requirements, 2 guidance statements, and 11 other statements.

Key Rules

Topic

Claims

7 rules
StatutoryInformativeAlways
[mpep-2182-a656eca3f62d6ba2bcdbb221]
Structure Must Clearly Link to Function for Means-Plus-Function Claims
Note:
The specification must clearly link disclosed structure to the recited function in means-plus-function claims as per 35 U.S.C. 112, sixth paragraph.

If the specification defines what is meant by the limitation for the purposes of the claimed invention, the examiner should interpret the limitation as having that meaning. If no definition is provided, some judgment must be exercised in determining the scope of the limitation. See, e.g., B. Braun Medical, Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997) (“We hold that, pursuant to [35 U.S.C. 112, sixth paragraph], structure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim. This duty to link or associate structure to function is the quid pro quo for the convenience of employing 112, paragraph 6.” The court refused to interpret a means-plus-function limitation as corresponding to a disclosed valve seat structure, as argued by patentee, since there was no indication in the specification or prosecution history that this structure corresponds to the recited function, and there was an explicitly clear association between that function and a traverse cross section bar structure disclosed in the specification.).

Jump to MPEP Source35 U.S.C. 112(f) – Means-Plus-Function (MPEP 2181-2186)Patent Application Content
MPEP GuidanceInformativeAlways
[mpep-2182-80d684246c46ea7b0fc42dd6]
Examiner Must Prove Identical Function for Means-Plus-Function Claims
Note:
The examiner must demonstrate that the prior art's structure or step performs the exact function claimed in the specification when only functional identity is taught.

The application of a prior art reference to a means- (or step-) plus-function limitation requires that the prior art element perform the identical function specified in the claim. However, if a prior art reference only teaches identity of function to that specified in a claim, then an examiner carries the initial burden of proof for showing that the prior art structure or step is the same as or equivalent to the structure, material, or acts described in the specification which has been identified as corresponding to the claimed means- (or step-) plus-function. Similarly, if the prior art reference teaches the identical structure or acts but is silent about performing the claimed function, a reasonable presumption is that the prior art structure inherently performs the same function. The examiner must provide a “sound basis for believing” that the prior art structure or acts would be capable of performing the claimed function. In re Spada, 911 F.2d 705, 708, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2114, subsection I, for more information on establishing inherency for functional limitations.

Jump to MPEP SourcePatent Application ContentPrior Art
MPEP GuidanceInformativeAlways
[mpep-2182-a37a2a2f93be14f853b77985]
Prior Art Structure Presumed to Perform Claimed Function
Note:
If prior art teaches identical structure but is silent on the claimed function, it is presumed to inherently perform that function.

The application of a prior art reference to a means- (or step-) plus-function limitation requires that the prior art element perform the identical function specified in the claim. However, if a prior art reference only teaches identity of function to that specified in a claim, then an examiner carries the initial burden of proof for showing that the prior art structure or step is the same as or equivalent to the structure, material, or acts described in the specification which has been identified as corresponding to the claimed means- (or step-) plus-function. Similarly, if the prior art reference teaches the identical structure or acts but is silent about performing the claimed function, a reasonable presumption is that the prior art structure inherently performs the same function. The examiner must provide a “sound basis for believing” that the prior art structure or acts would be capable of performing the claimed function. In re Spada, 911 F.2d 705, 708, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2114, subsection I, for more information on establishing inherency for functional limitations.

Jump to MPEP SourcePrior ArtPatent Application Content
MPEP GuidanceRequiredAlways
[mpep-2182-b548db4b9db9ae02482121f8]
Examiner Must Prove Structure Can Perform Function
Note:
The examiner must provide evidence that the prior art structure can perform the claimed function, based on a sound basis of belief.

The application of a prior art reference to a means- (or step-) plus-function limitation requires that the prior art element perform the identical function specified in the claim. However, if a prior art reference only teaches identity of function to that specified in a claim, then an examiner carries the initial burden of proof for showing that the prior art structure or step is the same as or equivalent to the structure, material, or acts described in the specification which has been identified as corresponding to the claimed means- (or step-) plus-function. Similarly, if the prior art reference teaches the identical structure or acts but is silent about performing the claimed function, a reasonable presumption is that the prior art structure inherently performs the same function. The examiner must provide a “sound basis for believing” that the prior art structure or acts would be capable of performing the claimed function. In re Spada, 911 F.2d 705, 708, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2114, subsection I, for more information on establishing inherency for functional limitations.

Jump to MPEP SourcePatent Application ContentPrior Art
MPEP GuidanceInformativeAlways
[mpep-2182-6a7b36f4a29475a2472841a6]
First Step in Construing Means-Plus-Function Claim Limitations
Note:
Define the particular function of the claim limitation before construing a means-plus-function claim.

The first step in construing a means-plus-function claim limitation is to define the particular function of the claim limitation. Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58 USPQ2d 1801, 1806 (Fed. Cir. 2001). “The court must construe the function of a means-plus-function limitation to include the limitations contained in the claim language, and only those limitations.” Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1113, 63 USPQ2d 1725, 1730 (Fed. Cir. 2002). The next step in construing a means-plus-function claim limitation is to look to the specification and identify the corresponding structure for that function. “Under this second step, ‘structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.’” Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210, 68 USPQ2d 1263, 1267 (Fed. Cir. 2003) (quoting B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997)).

Jump to MPEP SourceClaim Form RequirementsPatent Application Content
MPEP GuidanceInformativeAlways
[mpep-2182-e6a055d65a0dbfbd3cda5822]
Specification Must Identify Corresponding Structure
Note:
The specification must clearly link the structure to the function in a means-plus-function claim limitation.

The first step in construing a means-plus-function claim limitation is to define the particular function of the claim limitation. Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58 USPQ2d 1801, 1806 (Fed. Cir. 2001). “The court must construe the function of a means-plus-function limitation to include the limitations contained in the claim language, and only those limitations.” Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1113, 63 USPQ2d 1725, 1730 (Fed. Cir. 2002). The next step in construing a means-plus-function claim limitation is to look to the specification and identify the corresponding structure for that function. “Under this second step, ‘structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.’” Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210, 68 USPQ2d 1263, 1267 (Fed. Cir. 2003) (quoting B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997)).

Jump to MPEP SourcePatent Application ContentClaim Form Requirements
MPEP GuidanceInformativeAlways
[mpep-2182-43f131d492a7824cddcba45e]
Specification Must Clearly Link Structure to Function
Note:
The specification must clearly link the disclosed structure to the function in the claim for it to be considered corresponding structure.

The first step in construing a means-plus-function claim limitation is to define the particular function of the claim limitation. Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58 USPQ2d 1801, 1806 (Fed. Cir. 2001). “The court must construe the function of a means-plus-function limitation to include the limitations contained in the claim language, and only those limitations.” Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1113, 63 USPQ2d 1725, 1730 (Fed. Cir. 2002). The next step in construing a means-plus-function claim limitation is to look to the specification and identify the corresponding structure for that function. “Under this second step, ‘structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.’” Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210, 68 USPQ2d 1263, 1267 (Fed. Cir. 2003) (quoting B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997)).

Jump to MPEP SourcePatent Application ContentClaim Form Requirements
Topic

Claim Form Requirements

4 rules
MPEP GuidanceInformativeAlways
[mpep-2182-130f6769be6d9a98a25f147a]
Means-Plus-Function Claim Limitation Must Be Construed Based on Specification
Note:
The court must define the function of a means-plus-function claim limitation and identify corresponding structure in the specification that clearly links to the recited function.

The first step in construing a means-plus-function claim limitation is to define the particular function of the claim limitation. Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58 USPQ2d 1801, 1806 (Fed. Cir. 2001). “The court must construe the function of a means-plus-function limitation to include the limitations contained in the claim language, and only those limitations.” Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1113, 63 USPQ2d 1725, 1730 (Fed. Cir. 2002). The next step in construing a means-plus-function claim limitation is to look to the specification and identify the corresponding structure for that function. “Under this second step, ‘structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.’” Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210, 68 USPQ2d 1263, 1267 (Fed. Cir. 2003) (quoting B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997)).

Jump to MPEP SourceClaim Form RequirementsPatent Application Content
MPEP GuidanceRequiredAlways
[mpep-2182-acb0175e7a4406f5ed837e22]
Function of Means-Plus-Function Limitation Must Include Claim Language
Note:
The court must define the function of a means-plus-function claim limitation to include all limitations specified in the claim language.

The first step in construing a means-plus-function claim limitation is to define the particular function of the claim limitation. Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58 USPQ2d 1801, 1806 (Fed. Cir. 2001). “The court must construe the function of a means-plus-function limitation to include the limitations contained in the claim language, and only those limitations.” Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1113, 63 USPQ2d 1725, 1730 (Fed. Cir. 2002). The next step in construing a means-plus-function claim limitation is to look to the specification and identify the corresponding structure for that function. “Under this second step, ‘structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.’” Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210, 68 USPQ2d 1263, 1267 (Fed. Cir. 2003) (quoting B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997)).

Jump to MPEP SourceClaim Form RequirementsPatent Application Content
MPEP GuidanceInformativeAlways
[mpep-2182-d452417f0ab0965499bfe8e7]
Function of Means-Plus-Function Limitation Must Be Defined
Note:
The court must define the function of a means-plus-function claim limitation to include all limitations in the claim language.

The first step in construing a means-plus-function claim limitation is to define the particular function of the claim limitation. Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58 USPQ2d 1801, 1806 (Fed. Cir. 2001). “The court must construe the function of a means-plus-function limitation to include the limitations contained in the claim language, and only those limitations.” Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1113, 63 USPQ2d 1725, 1730 (Fed. Cir. 2002). The next step in construing a means-plus-function claim limitation is to look to the specification and identify the corresponding structure for that function. “Under this second step, ‘structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.’” Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210, 68 USPQ2d 1263, 1267 (Fed. Cir. 2003) (quoting B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997)).

Jump to MPEP SourceClaim Form RequirementsPatent Application Content
MPEP GuidanceInformativeAlways
[mpep-2182-72e4cb3ec6f5a13ac666f7d5]
Means-Plus-Function Claim Limitation Must Be Construed Based on Specification
Note:
The court must define the function of a means-plus-function claim limitation and identify corresponding structure in the specification that performs that function.

The first step in construing a means-plus-function claim limitation is to define the particular function of the claim limitation. Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58 USPQ2d 1801, 1806 (Fed. Cir. 2001). “The court must construe the function of a means-plus-function limitation to include the limitations contained in the claim language, and only those limitations.” Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1113, 63 USPQ2d 1725, 1730 (Fed. Cir. 2002). The next step in construing a means-plus-function claim limitation is to look to the specification and identify the corresponding structure for that function. “Under this second step, ‘structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.’” Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210, 68 USPQ2d 1263, 1267 (Fed. Cir. 2003) (quoting B. Braun Med. Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997)).

Jump to MPEP SourceClaim Form RequirementsPatent Application Content
Topic

Interpreting Claims (MPEP 2173.01)

2 rules
StatutoryRecommendedAlways
[mpep-2182-7def83aa7f6894b104324499]
Specification Defines Claimed Invention Meaning
Note:
Examiner must interpret claim limitations as defined by the specification unless no definition is provided, then judgment is required.

If the specification defines what is meant by the limitation for the purposes of the claimed invention, the examiner should interpret the limitation as having that meaning. If no definition is provided, some judgment must be exercised in determining the scope of the limitation. See, e.g., B. Braun Medical, Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997) (“We hold that, pursuant to [35 U.S.C. 112, sixth paragraph], structure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim. This duty to link or associate structure to function is the quid pro quo for the convenience of employing 112, paragraph 6.” The court refused to interpret a means-plus-function limitation as corresponding to a disclosed valve seat structure, as argued by patentee, since there was no indication in the specification or prosecution history that this structure corresponds to the recited function, and there was an explicitly clear association between that function and a traverse cross section bar structure disclosed in the specification.).

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)Patent Application Content
StatutoryInformativeAlways
[mpep-2182-7e0c2dbd89114c0622e6caa4]
Means-Plus-Function Limitation Must Be Clearly Linked to Structure
Note:
The court requires that a means-plus-function limitation be clearly linked to a specific structure in the specification for it to be interpreted as such.

If the specification defines what is meant by the limitation for the purposes of the claimed invention, the examiner should interpret the limitation as having that meaning. If no definition is provided, some judgment must be exercised in determining the scope of the limitation. See, e.g., B. Braun Medical, Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997) (“We hold that, pursuant to [35 U.S.C. 112, sixth paragraph], structure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim. This duty to link or associate structure to function is the quid pro quo for the convenience of employing 112, paragraph 6.” The court refused to interpret a means-plus-function limitation as corresponding to a disclosed valve seat structure, as argued by patentee, since there was no indication in the specification or prosecution history that this structure corresponds to the recited function, and there was an explicitly clear association between that function and a traverse cross section bar structure disclosed in the specification.).

Jump to MPEP SourceInterpreting Claims (MPEP 2173.01)35 U.S.C. 112(f) – Means-Plus-Function (MPEP 2181-2186)Patent Application Content
Topic

Corresponding Structure (MPEP 2182)

2 rules
StatutoryRequiredAlways
[mpep-2182-80d150a33ff9d9b8e143fab3]
Judgment Required for Limitation Interpretation Without Definition
Note:
When no definition is provided, the examiner must use judgment to determine the scope of a claimed limitation.

If the specification defines what is meant by the limitation for the purposes of the claimed invention, the examiner should interpret the limitation as having that meaning. If no definition is provided, some judgment must be exercised in determining the scope of the limitation. See, e.g., B. Braun Medical, Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997) (“We hold that, pursuant to [35 U.S.C. 112, sixth paragraph], structure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim. This duty to link or associate structure to function is the quid pro quo for the convenience of employing 112, paragraph 6.” The court refused to interpret a means-plus-function limitation as corresponding to a disclosed valve seat structure, as argued by patentee, since there was no indication in the specification or prosecution history that this structure corresponds to the recited function, and there was an explicitly clear association between that function and a traverse cross section bar structure disclosed in the specification.).

Jump to MPEP SourceCorresponding Structure (MPEP 2182)35 U.S.C. 112(f) – Means-Plus-Function (MPEP 2181-2186)Interpreting Claims (MPEP 2173.01)
StatutoryInformativeAlways
[mpep-2182-0c8f947444f4655fb1f0edb3]
Specification Must Clearly Link Structure to Function
Note:
The specification must clearly link any structure defined for a means-plus-function limitation to the recited function, fulfilling the requirement of 112, paragraph 6.

If the specification defines what is meant by the limitation for the purposes of the claimed invention, the examiner should interpret the limitation as having that meaning. If no definition is provided, some judgment must be exercised in determining the scope of the limitation. See, e.g., B. Braun Medical, Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997) (“We hold that, pursuant to [35 U.S.C. 112, sixth paragraph], structure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim. This duty to link or associate structure to function is the quid pro quo for the convenience of employing 112, paragraph 6.” The court refused to interpret a means-plus-function limitation as corresponding to a disclosed valve seat structure, as argued by patentee, since there was no indication in the specification or prosecution history that this structure corresponds to the recited function, and there was an explicitly clear association between that function and a traverse cross section bar structure disclosed in the specification.).

Jump to MPEP SourceCorresponding Structure (MPEP 2182)35 U.S.C. 112(f) – Means-Plus-Function (MPEP 2181-2186)Interpreting Claims (MPEP 2173.01)
Topic

Patent Application Content

2 rules
MPEP GuidanceRecommendedAlways
[mpep-2182-72bdeb6690f21984c198d3f2]
Means-Plus-Function Limitations Must Align with Specification
Note:
The means-plus-function limitations in claims must be interpreted based on the specific disclosure provided in the patent specification.

The means- (or step-) plus- function limitation should be interpreted in a manner consistent with the specification disclosure. The Federal Circuit explained the two step analysis involved in construing means- (or step-) plus- function limitations in Golight Inc. v. Wal-Mart Stores Inc., 355 F.3d 1327, 1333-34, 69 USPQ2d 1481, 1486 (Fed. Cir. 2004):

Jump to MPEP SourcePatent Application Content
MPEP GuidanceInformativeAlways
[mpep-2182-0f639c550ed861cf71deb92e]
Two Step Analysis for Construing Means-Plus-Function Limitations
Note:
The rule requires a two-step analysis to interpret means-plus-function limitations in a manner consistent with the specification disclosure.

The means- (or step-) plus- function limitation should be interpreted in a manner consistent with the specification disclosure. The Federal Circuit explained the two step analysis involved in construing means- (or step-) plus- function limitations in Golight Inc. v. Wal-Mart Stores Inc., 355 F.3d 1327, 1333-34, 69 USPQ2d 1481, 1486 (Fed. Cir. 2004):

Jump to MPEP SourcePatent Application Content

Citations

Primary topicCitation
Claims
Corresponding Structure (MPEP 2182)
Interpreting Claims (MPEP 2173.01)
35 U.S.C. § 112
ClaimsMPEP § 2114
Claim Form Requirements
Claims
Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1376, 58 USPQ2d 1801, 1806 (Fed. Cir. 2001)
Claim Form Requirements
Claims
Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210, 68 USPQ2d 1263, 1267 (Fed. Cir. 2003)
ClaimsIn re Spada, 911 F.2d 705, 708, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990)

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