MPEP § 2173.05(p) — Claim Directed to Product-By- Process or Product and Process (Annotated Rules)

§2173.05(p) Claim Directed to Product-By- Process or Product and Process

USPTO MPEP version: BlueIron's Update: 2026-01-17

This page consolidates and annotates all enforceable requirements under MPEP § 2173.05(p), 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.

Claim Directed to Product-By- Process or Product and Process

This section addresses Claim Directed to Product-By- Process or Product and Process. Primary authority: 35 U.S.C. 112(b) and 35 U.S.C. 112. Contains: 1 requirement, 2 permissions, and 6 other statements.

Key Rules

Topic

Alternative Limitations (MPEP 2173.05(h))

4 rules
StatutoryPermittedAlways
[mpep-2173-05-p-1a0aaada886666560fea7916]
Claim May Reference Process Without Being Objectionable Under Section 112(b)
Note:
A claim to a device, apparatus, manufacture, or composition of matter can reference the process in which it is intended to be used without being objectionable under section 112(b) as long as it is clear that the claim is directed to the product and not the process.

A product-by-process claim, which is a product claim that defines the claimed product in terms of the process by which it is made, is proper. Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 1354, 117 USPQ2d 1733, 1739 (Fed. Cir. 2016); In re Luck, 476 F.2d 650, 177 USPQ 523 (CCPA 1973); In re Pilkington, 411 F.2d 1345, 162 USPQ 145 (CCPA 1969); and In re Steppan, 394 F.2d 1013, 156 USPQ 143 (CCPA 1967). A claim to a device, apparatus, manufacture, or composition of matter may contain a reference to the process in which it is intended to be used without being objectionable under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph, so long as it is clear that the claim is directed to the product and not the process.

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))Negative Limitations (MPEP 2173.05(i))
StatutoryInformativeAlways
[mpep-2173-05-p-3db43bc71ff5b45f3c826c31]
Claim Must Not Include Both Apparatus and Method Steps
Note:
A claim cannot include both an apparatus and the method steps of using that apparatus, as it is considered indefinite under section 112(b) or pre-AIA section 112, second paragraph.

A single claim which claims both an apparatus and the method steps of using the apparatus is indefinite under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. See In re Katz Interactive Call Processing Patent Litigation, 639 F.3d 1303, 1318, 97 USPQ2d 1737, 1748-49 (Fed. Cir. 2011). In Katz, a claim directed to “[a] system with an interface means for providing automated voice messages…to certain of said individual callers, wherein said certain of said individual callers digitally enter data ” was determined to be indefinite because the italicized claim limitation is not directed to the system, but rather to actions of the individual callers, which creates confusion as to when direct infringement occurs. Katz, 639 F.3d at 1318, 97 USPQ2d at 1749 (citing IPXL Holdings v. Amazon.com, Inc., 430 F.3d 1377, 1384, 77 USPQ2d 1140, 1145 (Fed. Cir. 2005), in which a system claim that recited “an input means” and required a user to use the input means was found to be indefinite because it was unclear “whether infringement … occurs when one creates a system that allows the user [to use the input means], or whether infringement occurs when the user actually uses the input means.”); Ex parte Lyell, 17 USPQ2d 1548 (Bd. Pat. App. & Inter. 1990) (claim directed to an automatic transmission workstand and the method of using it held ambiguous and properly rejected under 35 U.S.C. 112, second paragraph).

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)
StatutoryRequiredAlways
[mpep-2173-05-p-3f9238e1b29062fc0bf380ff]
Claim Directed to Product-By-Process or Product and Process
Note:
A claim that combines both an apparatus and the method steps of using it is considered indefinite under section 112(b) if it creates confusion about when direct infringement occurs.

A single claim which claims both an apparatus and the method steps of using the apparatus is indefinite under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. See In re Katz Interactive Call Processing Patent Litigation, 639 F.3d 1303, 1318, 97 USPQ2d 1737, 1748-49 (Fed. Cir. 2011). In Katz, a claim directed to “[a] system with an interface means for providing automated voice messages…to certain of said individual callers, wherein said certain of said individual callers digitally enter data ” was determined to be indefinite because the italicized claim limitation is not directed to the system, but rather to actions of the individual callers, which creates confusion as to when direct infringement occurs. Katz, 639 F.3d at 1318, 97 USPQ2d at 1749 (citing IPXL Holdings v. Amazon.com, Inc., 430 F.3d 1377, 1384, 77 USPQ2d 1140, 1145 (Fed. Cir. 2005), in which a system claim that recited “an input means” and required a user to use the input means was found to be indefinite because it was unclear “whether infringement … occurs when one creates a system that allows the user [to use the input means], or whether infringement occurs when the user actually uses the input means.”); Ex parte Lyell, 17 USPQ2d 1548 (Bd. Pat. App. & Inter. 1990) (claim directed to an automatic transmission workstand and the method of using it held ambiguous and properly rejected under 35 U.S.C. 112, second paragraph).

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))Use Claims (MPEP 2173.05(q))
StatutoryPermittedAlways
[mpep-2173-05-p-04d0e02647cd4d7d835666f7]
Claim Must Focus on System Capabilities Not User Actions
Note:
A claim that describes a product with limitations focusing on the system's capabilities rather than specific user actions is considered definite under section 112(b) of the U.S. patent law.

In contrast, when a claim recites a product and additional limitations which focus on the capabilities of the system, not the specific actions or functions performed by the user, the claim may be definite under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. See Mastermine Software, Inc. v. Microsoft Corp., 874 F.3d 1307, 124 USPQ2d 1618 (Fed. Cir. 2017).

Jump to MPEP SourceAlternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))Determining Claim Definiteness (MPEP 2173.02)
Topic

Lack of Antecedent Basis (MPEP 2173.05(e))

2 rules
StatutoryInformativeAlways
[mpep-2173-05-p-be150c30d99133ac8ca4b6fc]
Proper Product-By-Process Claim
Note:
A claim defining a product by the process used to make it is acceptable as long as it clearly refers to the product and not the process.

A product-by-process claim, which is a product claim that defines the claimed product in terms of the process by which it is made, is proper. Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 1354, 117 USPQ2d 1733, 1739 (Fed. Cir. 2016); In re Luck, 476 F.2d 650, 177 USPQ 523 (CCPA 1973); In re Pilkington, 411 F.2d 1345, 162 USPQ 145 (CCPA 1969); and In re Steppan, 394 F.2d 1013, 156 USPQ 143 (CCPA 1967). A claim to a device, apparatus, manufacture, or composition of matter may contain a reference to the process in which it is intended to be used without being objectionable under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph, so long as it is clear that the claim is directed to the product and not the process.

Jump to MPEP SourceLack of Antecedent Basis (MPEP 2173.05(e))Human Organism Claims Prohibition35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)
StatutoryInformativeAlways
[mpep-2173-05-p-8b8dde464f6887b101a32a10]
Claim Directed to System and User Actions Indefinite
Note:
A claim that includes system limitations and requires user actions is considered indefinite, creating confusion about when direct infringement occurs.

A single claim which claims both an apparatus and the method steps of using the apparatus is indefinite under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. See In re Katz Interactive Call Processing Patent Litigation, 639 F.3d 1303, 1318, 97 USPQ2d 1737, 1748-49 (Fed. Cir. 2011). In Katz, a claim directed to “[a] system with an interface means for providing automated voice messages…to certain of said individual callers, wherein said certain of said individual callers digitally enter data ” was determined to be indefinite because the italicized claim limitation is not directed to the system, but rather to actions of the individual callers, which creates confusion as to when direct infringement occurs. Katz, 639 F.3d at 1318, 97 USPQ2d at 1749 (citing IPXL Holdings v. Amazon.com, Inc., 430 F.3d 1377, 1384, 77 USPQ2d 1140, 1145 (Fed. Cir. 2005), in which a system claim that recited “an input means” and required a user to use the input means was found to be indefinite because it was unclear “whether infringement … occurs when one creates a system that allows the user [to use the input means], or whether infringement occurs when the user actually uses the input means.”); Ex parte Lyell, 17 USPQ2d 1548 (Bd. Pat. App. & Inter. 1990) (claim directed to an automatic transmission workstand and the method of using it held ambiguous and properly rejected under 35 U.S.C. 112, second paragraph).

Jump to MPEP SourceLack of Antecedent Basis (MPEP 2173.05(e))When 112(f) Is Invoked (MPEP 2181)Human Organism Claims Prohibition
Topic

Human Organism Claims Prohibition

2 rules
StatutoryInformativeAlways
[mpep-2173-05-p-52fb4ab2fe1252870f471877]
Claim to Product May Reference Process
Note:
A product claim can refer to the process used to make it without violating the written description requirement, as long as the claim is directed to the product and not the process.

A product-by-process claim, which is a product claim that defines the claimed product in terms of the process by which it is made, is proper. Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 1354, 117 USPQ2d 1733, 1739 (Fed. Cir. 2016); In re Luck, 476 F.2d 650, 177 USPQ 523 (CCPA 1973); In re Pilkington, 411 F.2d 1345, 162 USPQ 145 (CCPA 1969); and In re Steppan, 394 F.2d 1013, 156 USPQ 143 (CCPA 1967). A claim to a device, apparatus, manufacture, or composition of matter may contain a reference to the process in which it is intended to be used without being objectionable under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph, so long as it is clear that the claim is directed to the product and not the process.

Jump to MPEP SourceHuman Organism Claims Prohibition35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)Alternative Limitations (MPEP 2173.05(h))
StatutoryInformativeAlways
[mpep-2173-05-p-0b123d7844199b38fc412c6b]
Claim Must Focus on System Capabilities
Note:
Claims must focus on the capabilities of the system rather than specific user actions to be definite under 35 U.S.C. 112(b).

In contrast, when a claim recites a product and additional limitations which focus on the capabilities of the system, not the specific actions or functions performed by the user, the claim may be definite under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. See Mastermine Software, Inc. v. Microsoft Corp., 874 F.3d 1307, 124 USPQ2d 1618 (Fed. Cir. 2017).

Jump to MPEP SourceHuman Organism Claims Prohibition35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)Alternative Limitations (MPEP 2173.05(h))
Topic

35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)

1 rules
StatutoryInformativeAlways
[mpep-2173-05-p-81b6ad5df1caeae2a4c38858]
Claim Must Not Mix System and User Actions
Note:
A claim must not mix elements of a system with actions performed by users, as it creates ambiguity about when infringement occurs.

A single claim which claims both an apparatus and the method steps of using the apparatus is indefinite under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. See In re Katz Interactive Call Processing Patent Litigation, 639 F.3d 1303, 1318, 97 USPQ2d 1737, 1748-49 (Fed. Cir. 2011). In Katz, a claim directed to “[a] system with an interface means for providing automated voice messages…to certain of said individual callers, wherein said certain of said individual callers digitally enter data ” was determined to be indefinite because the italicized claim limitation is not directed to the system, but rather to actions of the individual callers, which creates confusion as to when direct infringement occurs. Katz, 639 F.3d at 1318, 97 USPQ2d at 1749 (citing IPXL Holdings v. Amazon.com, Inc., 430 F.3d 1377, 1384, 77 USPQ2d 1140, 1145 (Fed. Cir. 2005), in which a system claim that recited “an input means” and required a user to use the input means was found to be indefinite because it was unclear “whether infringement … occurs when one creates a system that allows the user [to use the input means], or whether infringement occurs when the user actually uses the input means.”); Ex parte Lyell, 17 USPQ2d 1548 (Bd. Pat. App. & Inter. 1990) (claim directed to an automatic transmission workstand and the method of using it held ambiguous and properly rejected under 35 U.S.C. 112, second paragraph).

Jump to MPEP Source35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)Alternative Limitations (MPEP 2173.05(h))Lack of Antecedent Basis (MPEP 2173.05(e))

Citations

Primary topicCitation
35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)
Alternative Limitations (MPEP 2173.05(h))
Human Organism Claims Prohibition
Lack of Antecedent Basis (MPEP 2173.05(e))
35 U.S.C. § 112
35 U.S.C. 112(b) – Definiteness (MPEP 2171-2173)
Alternative Limitations (MPEP 2173.05(h))
Human Organism Claims Prohibition
Lack of Antecedent Basis (MPEP 2173.05(e))
35 U.S.C. § 112(b)
Alternative Limitations (MPEP 2173.05(h))
Human Organism Claims Prohibition
Lack of Antecedent Basis (MPEP 2173.05(e))
In re Luck, 476 F.2d 650, 177 USPQ 523 (CCPA 1973)
Alternative Limitations (MPEP 2173.05(h))
Human Organism Claims Prohibition
Lack of Antecedent Basis (MPEP 2173.05(e))
In re Pilkington, 411 F.2d 1345, 162 USPQ 145 (CCPA 1969)
Alternative Limitations (MPEP 2173.05(h))
Human Organism Claims Prohibition
Lack of Antecedent Basis (MPEP 2173.05(e))
In re Steppan, 394 F.2d 1013, 156 USPQ 143 (CCPA 1967)
Alternative Limitations (MPEP 2173.05(h))
Human Organism Claims Prohibition
Lack of Antecedent Basis (MPEP 2173.05(e))
Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 1354, 117 USPQ2d 1733, 1739 (Fed. Cir. 2016)
Alternative Limitations (MPEP 2173.05(h))
Human Organism Claims Prohibition
See Mastermine Software, Inc. v. Microsoft Corp., 874 F.3d 1307, 124 USPQ2d 1618 (Fed. Cir. 2017)

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: 2026-01-17