MPEP § 2113 — Product-by-Process Claims (Annotated Rules)

§2113 Product-by-Process Claims

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

This page consolidates and annotates all enforceable requirements under MPEP § 2113, 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.

Product-by-Process Claims

This section addresses Product-by-Process Claims. Primary authority: 35 U.S.C. 102 and 35 U.S.C. 103. Contains: 1 requirement, 1 prohibition, 3 guidance statements, and 14 other statements.

Key Rules

Topic

Anticipation/Novelty

14 rules
StatutoryRequiredAlways
[mpep-2113-b7d208ad1a9871225691e712]
Product Patency Over Process
Note:
A product-by-process claim must demonstrate the patentability of the resulting product, not just the process steps, making it difficult to determine patentability when prior art discloses similar products.

“[T]he lack of physical description in a product-by-process claim makes determination of the patentability of the claim more difficult, since in spite of the fact that the claim may recite only process limitations, it is the patentability of the product claimed and not of the recited process steps which must be established. We are therefore of the opinion that when the prior art discloses a product which reasonably appears to be either identical with or only slightly different than a product claimed in a product-by-process claim, a rejection based alternatively on either section 102 or section 103 of the statute is eminently fair and acceptable. As a practical matter, the Patent Office is not equipped to manufacture products by the myriad of processes put before it and then obtain prior art products and make physical comparisons therewith.” In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972). Office personnel should note that reliance on the alternative grounds of 35 U.S.C. 102 or 35 U.S.C. 103 does not eliminate the need to explain both the anticipation and obviousness aspects of the rejections.

Jump to MPEP SourceAnticipation/NoveltyObviousnessElements of Anticipation (MPEP 2131)
StatutoryInformativeAlways
[mpep-2113-8121513894cea4864e0d83f7]
Prior Art Product Identical to Claimed Product
Note:
When prior art discloses a product similar to that claimed in a product-by-process claim, a rejection based on either section 102 or 103 is acceptable.

“[T]he lack of physical description in a product-by-process claim makes determination of the patentability of the claim more difficult, since in spite of the fact that the claim may recite only process limitations, it is the patentability of the product claimed and not of the recited process steps which must be established. We are therefore of the opinion that when the prior art discloses a product which reasonably appears to be either identical with or only slightly different than a product claimed in a product-by-process claim, a rejection based alternatively on either section 102 or section 103 of the statute is eminently fair and acceptable. As a practical matter, the Patent Office is not equipped to manufacture products by the myriad of processes put before it and then obtain prior art products and make physical comparisons therewith.” In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972). Office personnel should note that reliance on the alternative grounds of 35 U.S.C. 102 or 35 U.S.C. 103 does not eliminate the need to explain both the anticipation and obviousness aspects of the rejections.

Jump to MPEP SourceAnticipation/NoveltyObviousnessElements of Anticipation (MPEP 2131)
StatutoryInformativeAlways
[mpep-2113-a5fc8095bfecb4d2b5613f1f]
Product Anticipation Over Process
Note:
When a product-by-process claim is made, the Patent Office can rely on prior art products to determine patentability rather than manufacturing and comparing physical products from various processes.

“[T]he lack of physical description in a product-by-process claim makes determination of the patentability of the claim more difficult, since in spite of the fact that the claim may recite only process limitations, it is the patentability of the product claimed and not of the recited process steps which must be established. We are therefore of the opinion that when the prior art discloses a product which reasonably appears to be either identical with or only slightly different than a product claimed in a product-by-process claim, a rejection based alternatively on either section 102 or section 103 of the statute is eminently fair and acceptable. As a practical matter, the Patent Office is not equipped to manufacture products by the myriad of processes put before it and then obtain prior art products and make physical comparisons therewith.” In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972). Office personnel should note that reliance on the alternative grounds of 35 U.S.C. 102 or 35 U.S.C. 103 does not eliminate the need to explain both the anticipation and obviousness aspects of the rejections.

Jump to MPEP SourceAnticipation/NoveltyObviousnessElements of Anticipation (MPEP 2131)
StatutoryRecommendedAlways
[mpep-2113-0ee098452d9c0c5a93ce4096]
Explain Both Anticipation and Obviousness in Rejections
Note:
Office personnel must provide explanations for both anticipation and obviousness when relying on alternative grounds of rejection under sections 102 or 103.

“[T]he lack of physical description in a product-by-process claim makes determination of the patentability of the claim more difficult, since in spite of the fact that the claim may recite only process limitations, it is the patentability of the product claimed and not of the recited process steps which must be established. We are therefore of the opinion that when the prior art discloses a product which reasonably appears to be either identical with or only slightly different than a product claimed in a product-by-process claim, a rejection based alternatively on either section 102 or section 103 of the statute is eminently fair and acceptable. As a practical matter, the Patent Office is not equipped to manufacture products by the myriad of processes put before it and then obtain prior art products and make physical comparisons therewith.” In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972). Office personnel should note that reliance on the alternative grounds of 35 U.S.C. 102 or 35 U.S.C. 103 does not eliminate the need to explain both the anticipation and obviousness aspects of the rejections.

Jump to MPEP SourceAnticipation/NoveltyObviousnessNovelty / Prior Art
MPEP GuidanceInformativeAlways
[mpep-2113-825c2f56467402ba732a9bad]
Product Determination Over Process
Note:
Patentability is based on the product itself, not its method of production. Even if a prior art product is made differently, it can still anticipate a product-by-process claim.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyElements of Anticipation (MPEP 2131)Novelty / Prior Art
MPEP GuidanceInformativeAlways
[mpep-2113-1ac25deecd1cc50e5b923674]
Product Anticipation Not Dependent On Production Method
Note:
A product in a claim is considered novel and non-obvious regardless of how it was produced, as long as it matches the product described in prior art.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyElements of Anticipation (MPEP 2131)Novelty / Prior Art
MPEP GuidanceInformativeAlways
[mpep-2113-b626a5dfe513fae7c8f0fbc8]
Same Product as Prior Art Invalidates Claim
Note:
If the product in a process claim is identical to or obvious from prior art, the claim is invalid regardless of the production method.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyObviousnessElements of Anticipation (MPEP 2131)
MPEP GuidanceInformativeAlways
[mpep-2113-8d5f96925cc5f10ae4db7965]
Same Product Anticipation
Note:
A product-by-process claim is unpatentable if the end product, regardless of production method, is the same as or obvious from a prior art product.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyElements of Anticipation (MPEP 2131)Novelty / Prior Art
MPEP GuidanceInformativeAlways
[mpep-2113-84ad181ce21c785dc8b63dde]
Same Product Anticipation
Note:
A product-by-process claim is unpatentable if the end product is the same as or obvious from a prior art product, regardless of how it was made.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyElements of Anticipation (MPEP 2131)Novelty / Prior Art
MPEP GuidanceInformativeAlways
[mpep-2113-9a21c45ea3baf9b92d0cd3ec]
Same Product Anticipation
Note:
A product-by-process claim is unpatentable if the end product, regardless of production method, is the same as or obvious from a prior art product.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyElements of Anticipation (MPEP 2131)Novelty / Prior Art
MPEP GuidanceInformativeAlways
[mpep-2113-3a305bd45a04c44d6d23c42c]
Same Product Anticipation Irrespective of Process
Note:
A patent is invalid if a product made by the process in a product-by-process claim is anticipated or obvious from prior art products, regardless of how those prior art products were made.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyElements of Anticipation (MPEP 2131)Novelty / Prior Art
MPEP GuidanceInformativeAlways
[mpep-2113-a04ab3fc82e319146a399ba1]
Product Anticipation Irrespective of Process
Note:
A product claim is considered anticipated by prior art even if made by a different process.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyElements of Anticipation (MPEP 2131)Novelty / Prior Art
MPEP GuidanceInformativeAlways
[mpep-2113-79b1285578e40cd778d5540a]
Same Product, Different Process Anticipation
Note:
A product-by-process claim is unpatentable if the same product can be made by a different process, even if both are novel.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyNovelty / Prior ArtElements of Anticipation (MPEP 2131)
MPEP GuidanceProhibitedAlways
[mpep-2113-883466c2753367094b92b28b]
Prior Art Product Can Anticipate But Not Infringe
Note:
A product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe such a claim.

“[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985) (citations omitted) (Claim was directed to a novolac color developer. The process of making the developer was allowed. The difference between the inventive process and the prior art was the addition of metal oxide and carboxylic acid as separate ingredients instead of adding the more expensive pre-reacted metal carboxylate. The product-by-process claim was rejected because the end product, in both the prior art and the allowed process, ends up containing metal carboxylate. The fact that the metal carboxylate is not directly added, but is instead produced in-situ does not change the end product.). Furthermore, “[b]ecause validity is determined based on the requirements of patentability, a patent is invalid if a product made by the process recited in a product-by-process claim is anticipated by or obvious from prior art products, even if those prior art products are made by different processes.” Amgen Inc. v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1370 n. 14, 92 USPQ2d 1289, 1312, n. 14 (Fed. Cir. 2009). See also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020) (“Biogen is certainly correct that the scope of composition and method of treatment claims is generally subject to distinctly different analyses. But where, as here, the novelty of the method of administration rests wholly on the novelty of the composition administered, which in turn rests on the novelty of the source limitation, the Amgen analysis will necessarily result in the same conclusion on anticipation for both forms of claims.”); United Therapeutics Corp. v Liquidia Techs., Inc., 74 F.4th 1360, 1373, 2023 USPQ2d 862 (Fed. Cir. 2023) (the court held that product-by-process claims were properly rejected as “anticipated by a disclosure of the same product irrespective of the processes by which they are made.”); and Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016). However, in the context of an infringement analysis, a product-by-process claim is only infringed by a product made by the process recited in the claim. Id. at 1370 (“a product in the prior art made by a different process can anticipate a product-by-process claim, but an accused product made by a different process cannot infringe a product-by-process claim”).

Jump to MPEP SourceAnticipation/NoveltyElements of Anticipation (MPEP 2131)Novelty / Prior Art
Topic

PTAB Jurisdiction

6 rules
MPEP GuidanceInformativeAlways
[mpep-2113-2ac809d305c1165d41ec8359]
Unexpected Properties Must Be Demonstrated
Note:
The claim must demonstrate unexpected properties of the factor when compared to prior art, even if the materials appear identical or similar.

See also Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. App. & Inter. 1989) (The prior art disclosed human nerve growth factor (b-NGF) isolated from human placental tissue. The claim was directed to b-NGF produced through genetic engineering techniques. The factor produced seemed to be substantially the same whether isolated from tissue or produced through genetic engineering. While the applicant questioned the purity of the prior art factor, no concrete evidence of an nonobvious difference was presented. The Board stated that the dispositive issue is whether the claimed factor exhibits any unexpected properties compared with the factor disclosed by the prior art. The Board further stated that the applicant should have made some comparison between the two factors to establish unexpected properties since the materials appeared to be identical or only slightly different.).

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
MPEP GuidanceInformativeAlways
[mpep-2113-68993ddbd1ea0a61e0b1bf48]
Claim Must Distinguish Genetic Engineering
Note:
The claim must demonstrate that b-NGF produced through genetic engineering techniques exhibits unexpected properties compared to the prior art factor isolated from tissue.

See also Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. App. & Inter. 1989) (The prior art disclosed human nerve growth factor (b-NGF) isolated from human placental tissue. The claim was directed to b-NGF produced through genetic engineering techniques. The factor produced seemed to be substantially the same whether isolated from tissue or produced through genetic engineering. While the applicant questioned the purity of the prior art factor, no concrete evidence of an nonobvious difference was presented. The Board stated that the dispositive issue is whether the claimed factor exhibits any unexpected properties compared with the factor disclosed by the prior art. The Board further stated that the applicant should have made some comparison between the two factors to establish unexpected properties since the materials appeared to be identical or only slightly different.).

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
MPEP GuidanceInformativeAlways
[mpep-2113-3e1671cfa8f906f0e4bdc03a]
Claims Must Describe Identical Product Regardless of Production Method
Note:
The claims must describe a product that is substantially the same whether isolated from tissue or produced through genetic engineering, as demonstrated by similar properties.

See also Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. App. & Inter. 1989) (The prior art disclosed human nerve growth factor (b-NGF) isolated from human placental tissue. The claim was directed to b-NGF produced through genetic engineering techniques. The factor produced seemed to be substantially the same whether isolated from tissue or produced through genetic engineering. While the applicant questioned the purity of the prior art factor, no concrete evidence of an nonobvious difference was presented. The Board stated that the dispositive issue is whether the claimed factor exhibits any unexpected properties compared with the factor disclosed by the prior art. The Board further stated that the applicant should have made some comparison between the two factors to establish unexpected properties since the materials appeared to be identical or only slightly different.).

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
MPEP GuidanceInformativeAlways
[mpep-2113-47920b61e6e05eb449b3bd4c]
No Evidence of Nonobvious Difference Required
Note:
The applicant must present concrete evidence to show that the claimed factor exhibits a nonobvious difference from the prior art factor.

See also Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. App. & Inter. 1989) (The prior art disclosed human nerve growth factor (b-NGF) isolated from human placental tissue. The claim was directed to b-NGF produced through genetic engineering techniques. The factor produced seemed to be substantially the same whether isolated from tissue or produced through genetic engineering. While the applicant questioned the purity of the prior art factor, no concrete evidence of an nonobvious difference was presented. The Board stated that the dispositive issue is whether the claimed factor exhibits any unexpected properties compared with the factor disclosed by the prior art. The Board further stated that the applicant should have made some comparison between the two factors to establish unexpected properties since the materials appeared to be identical or only slightly different.).

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresObviousness
MPEP GuidanceInformativeAlways
[mpep-2113-2afbbeea71c9fb66983c293d]
Claimed Factor Must Exhibit Unexpected Properties Compared to Prior Art
Note:
The Board requires that the claimed factor must demonstrate unexpected properties when compared to the factor disclosed in prior art for patentability.

See also Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. App. & Inter. 1989) (The prior art disclosed human nerve growth factor (b-NGF) isolated from human placental tissue. The claim was directed to b-NGF produced through genetic engineering techniques. The factor produced seemed to be substantially the same whether isolated from tissue or produced through genetic engineering. While the applicant questioned the purity of the prior art factor, no concrete evidence of an nonobvious difference was presented. The Board stated that the dispositive issue is whether the claimed factor exhibits any unexpected properties compared with the factor disclosed by the prior art. The Board further stated that the applicant should have made some comparison between the two factors to establish unexpected properties since the materials appeared to be identical or only slightly different.).

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
MPEP GuidanceRecommendedAlways
[mpep-2113-23f7cc589468f9489a2dfa71]
Applicant Must Compare Factors for Unexpected Properties
Note:
The applicant must compare the claimed factor with the prior art factor to demonstrate any unexpected properties due to their apparent similarity.

See also Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. App. & Inter. 1989) (The prior art disclosed human nerve growth factor (b-NGF) isolated from human placental tissue. The claim was directed to b-NGF produced through genetic engineering techniques. The factor produced seemed to be substantially the same whether isolated from tissue or produced through genetic engineering. While the applicant questioned the purity of the prior art factor, no concrete evidence of an nonobvious difference was presented. The Board stated that the dispositive issue is whether the claimed factor exhibits any unexpected properties compared with the factor disclosed by the prior art. The Board further stated that the applicant should have made some comparison between the two factors to establish unexpected properties since the materials appeared to be identical or only slightly different.).

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
Topic

Obviousness

4 rules
MPEP GuidanceInformativeAlways
[mpep-2113-1a28b879dc72e25efd3f17e9]
Patent Office Requires Lesser Burden of Proof for Obviousness
Note:
The Patent Office needs to show less evidence to prove a product-by-process claim is obvious compared to conventional claims.

“The Patent Office bears a lesser burden of proof in making out a case of prima facie obviousness for product-by-process claims because of their peculiar nature” than when a product is claimed in the conventional fashion. In re Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 1974). Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing an nonobvious difference between the claimed product and the prior art product. In re Marosi, 710 F.2d 799, 803, 218 USPQ 289, 292-33 (Fed. Cir. 1983) (The claims were directed to a zeolite manufactured by mixing together various inorganic materials in solution and heating the resultant gel to form a crystalline metal silicate essentially free of alkali metal. The prior art described a process of making a zeolite which, after ion exchange to remove alkali metal, appeared to be “essentially free of alkali metal.” The court upheld the rejection because the applicant had not come forward with any evidence that the prior art was not “essentially free of alkali metal” and therefore a different and nonobvious product.).

Jump to MPEP SourceObviousnessPrima Facie Case of Obviousness
MPEP GuidanceInformativeAlways
[mpep-2113-ceb3d37a2c8d737c9cd595c1]
Burden Shifts to Prove Nonobvious Difference
Note:
Once the examiner shows the claimed product is similar to prior art, the applicant must prove it is nonobvious.

“The Patent Office bears a lesser burden of proof in making out a case of prima facie obviousness for product-by-process claims because of their peculiar nature” than when a product is claimed in the conventional fashion. In re Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 1974). Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing an nonobvious difference between the claimed product and the prior art product. In re Marosi, 710 F.2d 799, 803, 218 USPQ 289, 292-33 (Fed. Cir. 1983) (The claims were directed to a zeolite manufactured by mixing together various inorganic materials in solution and heating the resultant gel to form a crystalline metal silicate essentially free of alkali metal. The prior art described a process of making a zeolite which, after ion exchange to remove alkali metal, appeared to be “essentially free of alkali metal.” The court upheld the rejection because the applicant had not come forward with any evidence that the prior art was not “essentially free of alkali metal” and therefore a different and nonobvious product.).

Jump to MPEP SourceObviousnessPrima Facie Case of Obviousness
MPEP GuidanceInformativeAlways
[mpep-2113-0276e5a5e04d42d84b4114b9]
Obviousness of Product from Process
Note:
If a product is claimed by process, the examiner must show it's similar to prior art; then burden shifts to applicant to prove nonobvious differences.

“The Patent Office bears a lesser burden of proof in making out a case of prima facie obviousness for product-by-process claims because of their peculiar nature” than when a product is claimed in the conventional fashion. In re Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 1974). Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing an nonobvious difference between the claimed product and the prior art product. In re Marosi, 710 F.2d 799, 803, 218 USPQ 289, 292-33 (Fed. Cir. 1983) (The claims were directed to a zeolite manufactured by mixing together various inorganic materials in solution and heating the resultant gel to form a crystalline metal silicate essentially free of alkali metal. The prior art described a process of making a zeolite which, after ion exchange to remove alkali metal, appeared to be “essentially free of alkali metal.” The court upheld the rejection because the applicant had not come forward with any evidence that the prior art was not “essentially free of alkali metal” and therefore a different and nonobvious product.).

Jump to MPEP SourceObviousnessPrima Facie Case of Obviousness
MPEP GuidanceInformativeAlways
[mpep-2113-03e5cdddc35dbe47e2f5bc02]
Applicant Must Prove Nonobvious Difference
Note:
The applicant must provide evidence that the prior art product is not essentially free of alkali metal to show a nonobvious difference from the claimed product.

“The Patent Office bears a lesser burden of proof in making out a case of prima facie obviousness for product-by-process claims because of their peculiar nature” than when a product is claimed in the conventional fashion. In re Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 1974). Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing an nonobvious difference between the claimed product and the prior art product. In re Marosi, 710 F.2d 799, 803, 218 USPQ 289, 292-33 (Fed. Cir. 1983) (The claims were directed to a zeolite manufactured by mixing together various inorganic materials in solution and heating the resultant gel to form a crystalline metal silicate essentially free of alkali metal. The prior art described a process of making a zeolite which, after ion exchange to remove alkali metal, appeared to be “essentially free of alkali metal.” The court upheld the rejection because the applicant had not come forward with any evidence that the prior art was not “essentially free of alkali metal” and therefore a different and nonobvious product.).

Jump to MPEP SourceObviousnessPrima Facie Case of Obviousness
Topic

Product-by-Process Claims

1 rules
MPEP GuidanceRecommendedAlways
[mpep-2113-ad33aa3a84485abdebc621ca]
Structure Implied by Process Steps for Product-by-Process Claims
Note:
When assessing patentability, consider the structural characteristics implied by the manufacturing process steps in product-by-process claims.

The structure implied by the process steps should be considered when assessing the patentability of product-by-process claims over the prior art, especially where the product can only be defined by the process steps by which the product is made, or where the manufacturing process steps would be expected to impart distinctive structural characteristics to the final product. See, e.g., In re Garnero, 412 F.2d 276, 279, 162 USPQ 221, 223 (CCPA 1979) (holding “interbonded by interfusion” to limit structure of the claimed composite and noting that terms such as “welded,” “intermixed,” “ground in place,” “press fitted,” and “etched” are capable of construction as structural limitations). See also In re Nordt Dev. Co., 881 F.3d 1371,1375-76, 125 USPQ2d 1817, 1820 (Fed. Cir. 2018)(holding “the specification demonstrates that ‘injected molded’ connotes an integral structure,” and discussing several cases since Garnero that held “limitations to convey structure even when they also describe a process of manufacture”).

Jump to MPEP SourceProduct-by-Process ClaimsPatent Application Content

Citations

Primary topicCitation
Anticipation/Novelty35 U.S.C. § 102
Anticipation/Novelty35 U.S.C. § 103
Anticipation/NoveltyIn re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972)
ObviousnessIn re Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 1974)
Product-by-Process ClaimsIn re Garnero, 412 F.2d 276, 279, 162 USPQ 221, 223 (CCPA 1979)
Anticipation/NoveltyIn re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985)
Anticipation/NoveltySee also Biogen MA Inc. v. EMD Serono, Inc., 976 F.3d 1326, 1334, 2020 USPQ2d 11129 (Fed. Cir. 2020)
Anticipation/Noveltyand Purdue Pharma v. Epic Pharma, 811 F.3d 1345, 117 USPQ2d 1733 (Fed. Cir. 2016)

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