MPEP § 2138.06 — “Reasonable Diligence” (Annotated Rules)

§2138.06 “Reasonable Diligence”

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

This page consolidates and annotates all enforceable requirements under MPEP § 2138.06, 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.

“Reasonable Diligence”

This section addresses “Reasonable Diligence”. Primary authority: 35 U.S.C. 100, 35 U.S.C. 102, and 35 U.S.C. 102(g). Contains: 4 requirements, 1 guidance statement, 4 permissions, and 14 other statements.

Key Rules

Topic

Registration Number on Signature

11 rules
StatutoryInformativeAlways
[mpep-2138-06-4d5e2939ec68be4a21c25de9]
Attorney Diligence Benefits Inventor
Note:
The attorney's effort in preparing and filing the patent application is considered beneficial to the inventor, with conception established by a draft finished at least six days before execution.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryInformativeAlways
[mpep-2138-06-777b2098425f64b1fc3c4033]
Conception Established at Draft Completion by Attorney
Note:
Conception is deemed established as early as the date a patent application draft, prepared by an attorney on behalf of the inventor, is finished.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryInformativeAlways
[mpep-2138-06-9619c9b64b71f096b1fb7e2d]
Disclosure Is Key to Conception
Note:
The focus of conception is on the disclosure made by a patent attorney, not just the signature. Reasonable diligence ensures the invention's details are adequately disclosed.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryInformativeAlways
[mpep-2138-06-379abf74db408136ba63f9ef]
Attorney Prepares on Behalf of True Inventive Entity
Note:
An attorney must prepare a patent application for the true inventive entity, not just named individuals.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryInformativeAlways
[mpep-2138-06-887416d10943ba9fa8f5f825]
Six-Day Deadline for Application Filing Acceptable
Note:
An attorney has six days to execute and file a patent application after conception, as established by Haskell v. Coleburne and Bey v. Kollonitsch.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryRequiredAlways
[mpep-2138-06-93575741cf0d9fcee7194b55]
Reasonable Diligence of Attorney in Preparing Patent Application
Note:
An attorney must work reasonably hard on a patent application during the critical period, even if they have a backlog of unrelated cases.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryInformativeAlways
[mpep-2138-06-8b9eccb05ce885c7b0d35adf]
Reasonable Diligence for Patent Application Preparation
Note:
An attorney must work reasonably hard on a patent application during the critical period to establish reasonable diligence.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryInformativeAlways
[mpep-2138-06-b083c7de5ae02cf202f90c31]
Attorney Diligence With Backlog
Note:
An attorney can meet reasonable diligence requirements by working on a backlog of unrelated cases in chronological order and expeditiously.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryPermittedAlways
[mpep-2138-06-a2415162b78fd6748cc702dd]
Work on Related Cases Can Contribute to Diligence
Note:
Attorney work on related cases that substantially contribute to an application's preparation can be credited as reasonable diligence.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryInformativeAlways
[mpep-2138-06-8919bfe4d81cfddc4abc39b7]
Daily Revision Not Required for Diligence
Note:
The absence of daily revisions between an inventor and their attorney during patent application preparation is not sufficient to determine abandonment or unreasonable delay.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
StatutoryInformativeAlways
[mpep-2138-06-d706af598b05cd362be5c69f]
Attorney Diligence for Patent Application
Note:
An attorney must prepare a patent application with reasonable diligence, considering the continuous critical period and acceptable timeframes.

The diligence of an attorney in preparing and filing patent application inures to the benefit of the inventor. Conception was established at least as early as the date a draft of a patent application was finished by a patent attorney on behalf of the inventor. Conception is less a matter of signature than it is one of disclosure. An attorney does not prepare a patent application on behalf of particular named persons, but on behalf of the true inventive entity. Six days to execute and file application is acceptable. Haskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable diligence is all that is required of the attorney. Reasonable diligence is established if the attorney worked reasonably hard on the application during the continuous critical period. If the attorney has a reasonable backlog of unrelated cases which the attorney takes up in chronological order and carries out expeditiously, that is sufficient. Work on a related case(s) that contributed substantially to the ultimate preparation of an application can be credited as diligence.). In “the preparation" of a patent application, "the absence of evidence that an inventor and his attorney revised or discussed the application on a daily basis is alone insufficient to determine that the invention was abandoned or unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016).

Jump to MPEP SourceRegistration Number on SignaturePractitioner Recognition and ConductSignature Requirements
Topic

PTAB Jurisdiction

7 rules
StatutoryInformativeAlways
[mpep-2138-06-d3313a1b4313dba166148e50]
Inactivity During Critical Period Does Not Invalidate Diligence Claim
Note:
The lack of activity during a critical period does not automatically invalidate a claim of reasonable diligence, as shown in In re Mulder.

Our decision in In re Mulder, 716 F.2d 1542, 1542-46 [219 USPQ 189] (Fed. Cir. 1983), does not instruct otherwise. The Board cites In re Mulder for the proposition that “[e]ven a short period of unexplained inactivity may be sufficient to defeat a claim of diligence.” …. In In re Mulder, a competing reference was published just days before the patent at issue was constructively reduced to practice. …. The patent owner was tasked with showing reasonable diligence during a critical period lasting only two days…. But the patent owner did not produce any evidence of diligence during the critical period…. Nor could it point to any activity during the months between the drafting of the application and the start of the critical period…. Although the critical period spanned just two days, we declined to excuse the patent owner's complete lack of evidence…. In re Mulder does not hold that an inventor's inactivity during a portion of the critical period can, without more, destroy a patent owner's claim of diligence.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryPermittedAlways
[mpep-2138-06-e8ec105c36d1212efe3f2df9]
Short Inactivity Can Invalidate Diligence Claim
Note:
Even a brief period of unexplained inactivity can undermine a patent owner's claim of reasonable diligence during critical periods.

Our decision in In re Mulder, 716 F.2d 1542, 1542-46 [219 USPQ 189] (Fed. Cir. 1983), does not instruct otherwise. The Board cites In re Mulder for the proposition that “[e]ven a short period of unexplained inactivity may be sufficient to defeat a claim of diligence.” …. In In re Mulder, a competing reference was published just days before the patent at issue was constructively reduced to practice. …. The patent owner was tasked with showing reasonable diligence during a critical period lasting only two days…. But the patent owner did not produce any evidence of diligence during the critical period…. Nor could it point to any activity during the months between the drafting of the application and the start of the critical period…. Although the critical period spanned just two days, we declined to excuse the patent owner's complete lack of evidence…. In re Mulder does not hold that an inventor's inactivity during a portion of the critical period can, without more, destroy a patent owner's claim of diligence.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryInformativeAlways
[mpep-2138-06-4bb665dd4f8b5fbb7ee6dbcc]
Competing Reference Before Constructive Reduction to Practice
Note:
Patent owner must show reasonable diligence during critical period if a competing reference is published just before constructive reduction to practice.

Our decision in In re Mulder, 716 F.2d 1542, 1542-46 [219 USPQ 189] (Fed. Cir. 1983), does not instruct otherwise. The Board cites In re Mulder for the proposition that “[e]ven a short period of unexplained inactivity may be sufficient to defeat a claim of diligence.” …. In In re Mulder, a competing reference was published just days before the patent at issue was constructively reduced to practice. …. The patent owner was tasked with showing reasonable diligence during a critical period lasting only two days…. But the patent owner did not produce any evidence of diligence during the critical period…. Nor could it point to any activity during the months between the drafting of the application and the start of the critical period…. Although the critical period spanned just two days, we declined to excuse the patent owner's complete lack of evidence…. In re Mulder does not hold that an inventor's inactivity during a portion of the critical period can, without more, destroy a patent owner's claim of diligence.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryInformativeAlways
[mpep-2138-06-2d223411632f51946aed6557]
Requirement for Reasonable Diligence During Short Critical Period
Note:
Patent owner must demonstrate reasonable diligence during a critical period, even if it lasts just two days.

Our decision in In re Mulder, 716 F.2d 1542, 1542-46 [219 USPQ 189] (Fed. Cir. 1983), does not instruct otherwise. The Board cites In re Mulder for the proposition that “[e]ven a short period of unexplained inactivity may be sufficient to defeat a claim of diligence.” …. In In re Mulder, a competing reference was published just days before the patent at issue was constructively reduced to practice. …. The patent owner was tasked with showing reasonable diligence during a critical period lasting only two days…. But the patent owner did not produce any evidence of diligence during the critical period…. Nor could it point to any activity during the months between the drafting of the application and the start of the critical period…. Although the critical period spanned just two days, we declined to excuse the patent owner's complete lack of evidence…. In re Mulder does not hold that an inventor's inactivity during a portion of the critical period can, without more, destroy a patent owner's claim of diligence.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryInformativeAlways
[mpep-2138-06-71d8f938fa8feee986b69b73]
Requirement for Diligence During Critical Period
Note:
Patent owner must demonstrate reasonable diligence during the critical period and show activity before the start of the critical period.

Our decision in In re Mulder, 716 F.2d 1542, 1542-46 [219 USPQ 189] (Fed. Cir. 1983), does not instruct otherwise. The Board cites In re Mulder for the proposition that “[e]ven a short period of unexplained inactivity may be sufficient to defeat a claim of diligence.” …. In In re Mulder, a competing reference was published just days before the patent at issue was constructively reduced to practice. …. The patent owner was tasked with showing reasonable diligence during a critical period lasting only two days…. But the patent owner did not produce any evidence of diligence during the critical period…. Nor could it point to any activity during the months between the drafting of the application and the start of the critical period…. Although the critical period spanned just two days, we declined to excuse the patent owner's complete lack of evidence…. In re Mulder does not hold that an inventor's inactivity during a portion of the critical period can, without more, destroy a patent owner's claim of diligence.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryInformativeAlways
[mpep-2138-06-0b57ba328839becddee6394e]
Patent Owner Must Provide Evidence of Diligence During Short Critical Period
Note:
The patent owner must present evidence of diligence during a critical period, even if it is just two days long. Failure to provide such evidence can result in the rejection of the claim of diligence.

Our decision in In re Mulder, 716 F.2d 1542, 1542-46 [219 USPQ 189] (Fed. Cir. 1983), does not instruct otherwise. The Board cites In re Mulder for the proposition that “[e]ven a short period of unexplained inactivity may be sufficient to defeat a claim of diligence.” …. In In re Mulder, a competing reference was published just days before the patent at issue was constructively reduced to practice. …. The patent owner was tasked with showing reasonable diligence during a critical period lasting only two days…. But the patent owner did not produce any evidence of diligence during the critical period…. Nor could it point to any activity during the months between the drafting of the application and the start of the critical period…. Although the critical period spanned just two days, we declined to excuse the patent owner's complete lack of evidence…. In re Mulder does not hold that an inventor's inactivity during a portion of the critical period can, without more, destroy a patent owner's claim of diligence.

Jump to MPEP SourcePTAB JurisdictionPTAB Contested Case ProceduresEx Parte Appeals to PTAB
StatutoryPermittedAlways
[mpep-2138-06-2ac24c4c7f5579819004cdce]
Inactivity During Critical Period Does Not Destroy Diligence Claim
Note:
An inventor's inactivity during a portion of the critical period does not automatically destroy their claim of diligence unless there is no evidence of any activity during that time.

Our decision in In re Mulder, 716 F.2d 1542, 1542-46 [219 USPQ 189] (Fed. Cir. 1983), does not instruct otherwise. The Board cites In re Mulder for the proposition that “[e]ven a short period of unexplained inactivity may be sufficient to defeat a claim of diligence.” …. In In re Mulder, a competing reference was published just days before the patent at issue was constructively reduced to practice. …. The patent owner was tasked with showing reasonable diligence during a critical period lasting only two days…. But the patent owner did not produce any evidence of diligence during the critical period…. Nor could it point to any activity during the months between the drafting of the application and the start of the critical period…. Although the critical period spanned just two days, we declined to excuse the patent owner's complete lack of evidence…. In re Mulder does not hold that an inventor's inactivity during a portion of the critical period can, without more, destroy a patent owner's claim of diligence.

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

Testimony Request Procedures

6 rules
StatutoryRequiredAlways
[mpep-2138-06-91cbb8c653e1f620705c715a]
Work Must Directly Support Reduction to Practice
Note:
The work relied upon to show reasonable diligence must be directly related to reducing the invention to practice, not just related activities.

The work relied upon to show reasonable diligence must be directly related to the reduction to practice of the invention in issue. Naber v. Cricchi, 567 F.2d 382, 384, 196 USPQ 294, 296 (CCPA 1977), cert. denied, 439 U.S. 826 (1978). See also Scott v. Koyama, 281 F.3d 1243, 1248-49, 61 USPQ2d 1856, 1859 (Fed. Cir. 2002) (Activities directed at building a plant to practice the claimed process of producing tetrafluoroethane on a large scale constituted efforts toward actual reduction to practice, and thus were evidence of diligence. The court distinguished cases where diligence was not found because inventors either discontinued development or failed to complete the invention while pursuing financing or other commercial activity.); In re Jolley, 308 F.3d 1317, 1326-27, 64 USPQ2d 1901, 1908-09 (Fed. Cir. 2002) (diligence found based on research and procurement activities related to the subject matter of the interference count). “[U]nder some circumstances an inventor should also be able to rely on work on closely related inventions as support for diligence toward the reduction to practice on an invention in issue.” Ginos v. Nedelec, 220 USPQ 831, 836 (Bd. Pat. Inter. 1983) (work on other closely related compounds that were considered to be part of the same invention and which were included as part of a grandparent application). “The work relied upon must be directed to attaining a reduction to practice of the subject matter of the counts. It is not sufficient that the activity relied on concerns related subject matter.” Gunn v. Bosch, 181 USPQ 758, 761 (Bd. Pat. Inter. 1973) (An actual reduction to practice of the invention at issue which occurred when the inventor was working on a different invention “was fortuitous, and not the result of a continuous intent or effort to reduce to practice the invention here in issue. Such fortuitousness is inconsistent with the exercise of diligence toward reduction to practice of that invention.” 181 USPQ at 761. Furthermore, evidence drawn towards work on improvement of samples or specimens generally already in use at the time of conception that are but one element of the oscillator circuit of the count does not show diligence towards the construction and testing of the overall combination.); Broos v. Barton, 142 F.2d 690, 691, 61 USPQ 447, 448 (CCPA 1944) (preparation of application in U.S. for foreign filing constitutes diligence); De Solms v. Schoenwald, 15 USPQ2d 1507 (Bd. Pat. App. & Inter. 1990) (principles of diligence must be given to inventor’s circumstances including skill and time; requirement of corroboration applies only to testimony of inventor); Huelster v. Reiter, 168 F.2d 542, 78 USPQ 82 (CCPA 1948) (an inventor who was not able to make an actual reduction to practice of the invention, must also show why constructive reduction to practice by filing an application was not possible).

Jump to MPEP SourceTestimony Request ProceduresUSPTO Employee TestimonyForeign Filing Licenses
StatutoryInformativeAlways
[mpep-2138-06-0ddc21fe78af11f930b0abff]
Diligence Must Be Shown for Reduction to Practice
Note:
The court requires that inventors demonstrate continuous efforts towards reducing their invention to practice, distinguishing cases where development was discontinued or abandoned during financing activities.

The work relied upon to show reasonable diligence must be directly related to the reduction to practice of the invention in issue. Naber v. Cricchi, 567 F.2d 382, 384, 196 USPQ 294, 296 (CCPA 1977), cert. denied, 439 U.S. 826 (1978). See also Scott v. Koyama, 281 F.3d 1243, 1248-49, 61 USPQ2d 1856, 1859 (Fed. Cir. 2002) (Activities directed at building a plant to practice the claimed process of producing tetrafluoroethane on a large scale constituted efforts toward actual reduction to practice, and thus were evidence of diligence. The court distinguished cases where diligence was not found because inventors either discontinued development or failed to complete the invention while pursuing financing or other commercial activity.); In re Jolley, 308 F.3d 1317, 1326-27, 64 USPQ2d 1901, 1908-09 (Fed. Cir. 2002) (diligence found based on research and procurement activities related to the subject matter of the interference count). “[U]nder some circumstances an inventor should also be able to rely on work on closely related inventions as support for diligence toward the reduction to practice on an invention in issue.” Ginos v. Nedelec, 220 USPQ 831, 836 (Bd. Pat. Inter. 1983) (work on other closely related compounds that were considered to be part of the same invention and which were included as part of a grandparent application). “The work relied upon must be directed to attaining a reduction to practice of the subject matter of the counts. It is not sufficient that the activity relied on concerns related subject matter.” Gunn v. Bosch, 181 USPQ 758, 761 (Bd. Pat. Inter. 1973) (An actual reduction to practice of the invention at issue which occurred when the inventor was working on a different invention “was fortuitous, and not the result of a continuous intent or effort to reduce to practice the invention here in issue. Such fortuitousness is inconsistent with the exercise of diligence toward reduction to practice of that invention.” 181 USPQ at 761. Furthermore, evidence drawn towards work on improvement of samples or specimens generally already in use at the time of conception that are but one element of the oscillator circuit of the count does not show diligence towards the construction and testing of the overall combination.); Broos v. Barton, 142 F.2d 690, 691, 61 USPQ 447, 448 (CCPA 1944) (preparation of application in U.S. for foreign filing constitutes diligence); De Solms v. Schoenwald, 15 USPQ2d 1507 (Bd. Pat. App. & Inter. 1990) (principles of diligence must be given to inventor’s circumstances including skill and time; requirement of corroboration applies only to testimony of inventor); Huelster v. Reiter, 168 F.2d 542, 78 USPQ 82 (CCPA 1948) (an inventor who was not able to make an actual reduction to practice of the invention, must also show why constructive reduction to practice by filing an application was not possible).

Jump to MPEP SourceTestimony Request ProceduresUSPTO Employee TestimonyForeign Filing Licenses
StatutoryRecommendedAlways
[mpep-2138-06-582826092bbb1d32ba27c76f]
Inventor Can Rely on Closely Related Work for Diligence
Note:
An inventor may use work on closely related inventions as evidence of diligence towards reducing the invention in issue to practice, provided the work is part of the same inventive concept.

The work relied upon to show reasonable diligence must be directly related to the reduction to practice of the invention in issue. Naber v. Cricchi, 567 F.2d 382, 384, 196 USPQ 294, 296 (CCPA 1977), cert. denied, 439 U.S. 826 (1978). See also Scott v. Koyama, 281 F.3d 1243, 1248-49, 61 USPQ2d 1856, 1859 (Fed. Cir. 2002) (Activities directed at building a plant to practice the claimed process of producing tetrafluoroethane on a large scale constituted efforts toward actual reduction to practice, and thus were evidence of diligence. The court distinguished cases where diligence was not found because inventors either discontinued development or failed to complete the invention while pursuing financing or other commercial activity.); In re Jolley, 308 F.3d 1317, 1326-27, 64 USPQ2d 1901, 1908-09 (Fed. Cir. 2002) (diligence found based on research and procurement activities related to the subject matter of the interference count). “[U]nder some circumstances an inventor should also be able to rely on work on closely related inventions as support for diligence toward the reduction to practice on an invention in issue.” Ginos v. Nedelec, 220 USPQ 831, 836 (Bd. Pat. Inter. 1983) (work on other closely related compounds that were considered to be part of the same invention and which were included as part of a grandparent application). “The work relied upon must be directed to attaining a reduction to practice of the subject matter of the counts. It is not sufficient that the activity relied on concerns related subject matter.” Gunn v. Bosch, 181 USPQ 758, 761 (Bd. Pat. Inter. 1973) (An actual reduction to practice of the invention at issue which occurred when the inventor was working on a different invention “was fortuitous, and not the result of a continuous intent or effort to reduce to practice the invention here in issue. Such fortuitousness is inconsistent with the exercise of diligence toward reduction to practice of that invention.” 181 USPQ at 761. Furthermore, evidence drawn towards work on improvement of samples or specimens generally already in use at the time of conception that are but one element of the oscillator circuit of the count does not show diligence towards the construction and testing of the overall combination.); Broos v. Barton, 142 F.2d 690, 691, 61 USPQ 447, 448 (CCPA 1944) (preparation of application in U.S. for foreign filing constitutes diligence); De Solms v. Schoenwald, 15 USPQ2d 1507 (Bd. Pat. App. & Inter. 1990) (principles of diligence must be given to inventor’s circumstances including skill and time; requirement of corroboration applies only to testimony of inventor); Huelster v. Reiter, 168 F.2d 542, 78 USPQ 82 (CCPA 1948) (an inventor who was not able to make an actual reduction to practice of the invention, must also show why constructive reduction to practice by filing an application was not possible).

Jump to MPEP SourceTestimony Request ProceduresUSPTO Employee TestimonyForeign Filing Licenses
StatutoryRequiredAlways
[mpep-2138-06-72d86d257e02db6ca1ee23f2]
Work Must Directly Attain Reduction to Practice of Invention
Note:
The work relied upon must be directly related to achieving the reduction to practice of the specific invention in question, not just related subject matter.

The work relied upon to show reasonable diligence must be directly related to the reduction to practice of the invention in issue. Naber v. Cricchi, 567 F.2d 382, 384, 196 USPQ 294, 296 (CCPA 1977), cert. denied, 439 U.S. 826 (1978). See also Scott v. Koyama, 281 F.3d 1243, 1248-49, 61 USPQ2d 1856, 1859 (Fed. Cir. 2002) (Activities directed at building a plant to practice the claimed process of producing tetrafluoroethane on a large scale constituted efforts toward actual reduction to practice, and thus were evidence of diligence. The court distinguished cases where diligence was not found because inventors either discontinued development or failed to complete the invention while pursuing financing or other commercial activity.); In re Jolley, 308 F.3d 1317, 1326-27, 64 USPQ2d 1901, 1908-09 (Fed. Cir. 2002) (diligence found based on research and procurement activities related to the subject matter of the interference count). “[U]nder some circumstances an inventor should also be able to rely on work on closely related inventions as support for diligence toward the reduction to practice on an invention in issue.” Ginos v. Nedelec, 220 USPQ 831, 836 (Bd. Pat. Inter. 1983) (work on other closely related compounds that were considered to be part of the same invention and which were included as part of a grandparent application). “The work relied upon must be directed to attaining a reduction to practice of the subject matter of the counts. It is not sufficient that the activity relied on concerns related subject matter.” Gunn v. Bosch, 181 USPQ 758, 761 (Bd. Pat. Inter. 1973) (An actual reduction to practice of the invention at issue which occurred when the inventor was working on a different invention “was fortuitous, and not the result of a continuous intent or effort to reduce to practice the invention here in issue. Such fortuitousness is inconsistent with the exercise of diligence toward reduction to practice of that invention.” 181 USPQ at 761. Furthermore, evidence drawn towards work on improvement of samples or specimens generally already in use at the time of conception that are but one element of the oscillator circuit of the count does not show diligence towards the construction and testing of the overall combination.); Broos v. Barton, 142 F.2d 690, 691, 61 USPQ 447, 448 (CCPA 1944) (preparation of application in U.S. for foreign filing constitutes diligence); De Solms v. Schoenwald, 15 USPQ2d 1507 (Bd. Pat. App. & Inter. 1990) (principles of diligence must be given to inventor’s circumstances including skill and time; requirement of corroboration applies only to testimony of inventor); Huelster v. Reiter, 168 F.2d 542, 78 USPQ 82 (CCPA 1948) (an inventor who was not able to make an actual reduction to practice of the invention, must also show why constructive reduction to practice by filing an application was not possible).

Jump to MPEP SourceTestimony Request ProceduresUSPTO Employee TestimonyForeign Filing Licenses
StatutoryInformativeAlways
[mpep-2138-06-d284c8b81fff546f69b3ec2a]
Diligence Not Shown for Fortuitous Reduction to Practice
Note:
The rule states that an actual reduction to practice achieved while working on a different invention is not evidence of diligence toward the original invention if it was not the result of continuous intent or effort.

The work relied upon to show reasonable diligence must be directly related to the reduction to practice of the invention in issue. Naber v. Cricchi, 567 F.2d 382, 384, 196 USPQ 294, 296 (CCPA 1977), cert. denied, 439 U.S. 826 (1978). See also Scott v. Koyama, 281 F.3d 1243, 1248-49, 61 USPQ2d 1856, 1859 (Fed. Cir. 2002) (Activities directed at building a plant to practice the claimed process of producing tetrafluoroethane on a large scale constituted efforts toward actual reduction to practice, and thus were evidence of diligence. The court distinguished cases where diligence was not found because inventors either discontinued development or failed to complete the invention while pursuing financing or other commercial activity.); In re Jolley, 308 F.3d 1317, 1326-27, 64 USPQ2d 1901, 1908-09 (Fed. Cir. 2002) (diligence found based on research and procurement activities related to the subject matter of the interference count). “[U]nder some circumstances an inventor should also be able to rely on work on closely related inventions as support for diligence toward the reduction to practice on an invention in issue.” Ginos v. Nedelec, 220 USPQ 831, 836 (Bd. Pat. Inter. 1983) (work on other closely related compounds that were considered to be part of the same invention and which were included as part of a grandparent application). “The work relied upon must be directed to attaining a reduction to practice of the subject matter of the counts. It is not sufficient that the activity relied on concerns related subject matter.” Gunn v. Bosch, 181 USPQ 758, 761 (Bd. Pat. Inter. 1973) (An actual reduction to practice of the invention at issue which occurred when the inventor was working on a different invention “was fortuitous, and not the result of a continuous intent or effort to reduce to practice the invention here in issue. Such fortuitousness is inconsistent with the exercise of diligence toward reduction to practice of that invention.” 181 USPQ at 761. Furthermore, evidence drawn towards work on improvement of samples or specimens generally already in use at the time of conception that are but one element of the oscillator circuit of the count does not show diligence towards the construction and testing of the overall combination.); Broos v. Barton, 142 F.2d 690, 691, 61 USPQ 447, 448 (CCPA 1944) (preparation of application in U.S. for foreign filing constitutes diligence); De Solms v. Schoenwald, 15 USPQ2d 1507 (Bd. Pat. App. & Inter. 1990) (principles of diligence must be given to inventor’s circumstances including skill and time; requirement of corroboration applies only to testimony of inventor); Huelster v. Reiter, 168 F.2d 542, 78 USPQ 82 (CCPA 1948) (an inventor who was not able to make an actual reduction to practice of the invention, must also show why constructive reduction to practice by filing an application was not possible).

Jump to MPEP SourceTestimony Request ProceduresUSPTO Employee TestimonyForeign Filing Licenses
StatutoryRequiredAlways
[mpep-2138-06-09417724e72ec2ebb8b8c148]
Evidence of Diligent Reduction to Practice Required
Note:
Inventors must provide evidence demonstrating their diligent efforts towards reducing the invention to practice, focusing on activities directly related to achieving this goal.

The work relied upon to show reasonable diligence must be directly related to the reduction to practice of the invention in issue. Naber v. Cricchi, 567 F.2d 382, 384, 196 USPQ 294, 296 (CCPA 1977), cert. denied, 439 U.S. 826 (1978). See also Scott v. Koyama, 281 F.3d 1243, 1248-49, 61 USPQ2d 1856, 1859 (Fed. Cir. 2002) (Activities directed at building a plant to practice the claimed process of producing tetrafluoroethane on a large scale constituted efforts toward actual reduction to practice, and thus were evidence of diligence. The court distinguished cases where diligence was not found because inventors either discontinued development or failed to complete the invention while pursuing financing or other commercial activity.); In re Jolley, 308 F.3d 1317, 1326-27, 64 USPQ2d 1901, 1908-09 (Fed. Cir. 2002) (diligence found based on research and procurement activities related to the subject matter of the interference count). “[U]nder some circumstances an inventor should also be able to rely on work on closely related inventions as support for diligence toward the reduction to practice on an invention in issue.” Ginos v. Nedelec, 220 USPQ 831, 836 (Bd. Pat. Inter. 1983) (work on other closely related compounds that were considered to be part of the same invention and which were included as part of a grandparent application). “The work relied upon must be directed to attaining a reduction to practice of the subject matter of the counts. It is not sufficient that the activity relied on concerns related subject matter.” Gunn v. Bosch, 181 USPQ 758, 761 (Bd. Pat. Inter. 1973) (An actual reduction to practice of the invention at issue which occurred when the inventor was working on a different invention “was fortuitous, and not the result of a continuous intent or effort to reduce to practice the invention here in issue. Such fortuitousness is inconsistent with the exercise of diligence toward reduction to practice of that invention.” 181 USPQ at 761. Furthermore, evidence drawn towards work on improvement of samples or specimens generally already in use at the time of conception that are but one element of the oscillator circuit of the count does not show diligence towards the construction and testing of the overall combination.); Broos v. Barton, 142 F.2d 690, 691, 61 USPQ 447, 448 (CCPA 1944) (preparation of application in U.S. for foreign filing constitutes diligence); De Solms v. Schoenwald, 15 USPQ2d 1507 (Bd. Pat. App. & Inter. 1990) (principles of diligence must be given to inventor’s circumstances including skill and time; requirement of corroboration applies only to testimony of inventor); Huelster v. Reiter, 168 F.2d 542, 78 USPQ 82 (CCPA 1948) (an inventor who was not able to make an actual reduction to practice of the invention, must also show why constructive reduction to practice by filing an application was not possible).

Jump to MPEP SourceTestimony Request ProceduresUSPTO Employee TestimonyForeign Filing Licenses
Topic

Ordering Certified Copies

2 rules
StatutoryPermittedAlways
[mpep-2138-06-89c4f729282a30111c3cbe27]
Diligence Period for First Conceiver but Second Reducer
Note:
The diligence period starts just before the first reducer enters the field and ends when the first conceiver reduces to practice.

The critical period for diligence for a first conceiver but second reducer begins not at the time of conception of the first conceiver but just prior to the entry in the field of the party who was first to reduce to practice and continues until the first conceiver reduces to practice. Hull v. Davenport, 90 F.2d 103, 105, 33 USPQ 506, 508 (CCPA 1937) (“lack of diligence from the time of conception to the time immediately preceding the conception date of the second conceiver is not regarded as of importance except as it may have a bearing upon his subsequent acts”). What serves as the entry date into the field of a first reducer is dependent upon what is being relied on by the first reducer, e.g., conception plus reasonable diligence to reduction to practice (Fritsch v. Lin, 21 USPQ2d 1731, 1734 (Bd. Pat. App. & Inter. 1991), Emery v. Ronden, 188 USPQ 264, 268 (Bd. Pat. Inter. 1974)); an actual reduction to practice or a constructive reduction to practice by the filing of either a U.S. application (Rebstock v. Flouret, 191 USPQ 342, 345 (Bd. Pat. Inter. 1975)) or reliance upon priority under 35 U.S.C. 119 of a foreign application (Justus v. Appenzeller, 177 USPQ 332, 339 (Bd. Pat. Inter. 1971) (chain of priorities under 35 U.S.C. 119 and 120, priority under 35 U.S.C. 119 denied for failure to supply certified copy of the foreign application during pendency of the application that was filed within the twelve month period prescribed by 35 U.S.C. 119)).

Jump to MPEP SourceOrdering Certified CopiesCertified Copies of DocumentsPTAB Contested Case Procedures
StatutoryInformativeAlways
[mpep-2138-06-fe77a81268e7711983c52199]
First Reducer Entry Date Depends on Reduction to Practice
Note:
The date a first reducer enters the field is based on their reduction to practice, whether actual or constructive through filing a U.S. application or relying on foreign priority.

The critical period for diligence for a first conceiver but second reducer begins not at the time of conception of the first conceiver but just prior to the entry in the field of the party who was first to reduce to practice and continues until the first conceiver reduces to practice. Hull v. Davenport, 90 F.2d 103, 105, 33 USPQ 506, 508 (CCPA 1937) (“lack of diligence from the time of conception to the time immediately preceding the conception date of the second conceiver is not regarded as of importance except as it may have a bearing upon his subsequent acts”). What serves as the entry date into the field of a first reducer is dependent upon what is being relied on by the first reducer, e.g., conception plus reasonable diligence to reduction to practice (Fritsch v. Lin, 21 USPQ2d 1731, 1734 (Bd. Pat. App. & Inter. 1991), Emery v. Ronden, 188 USPQ 264, 268 (Bd. Pat. Inter. 1974)); an actual reduction to practice or a constructive reduction to practice by the filing of either a U.S. application (Rebstock v. Flouret, 191 USPQ 342, 345 (Bd. Pat. Inter. 1975)) or reliance upon priority under 35 U.S.C. 119 of a foreign application (Justus v. Appenzeller, 177 USPQ 332, 339 (Bd. Pat. Inter. 1971) (chain of priorities under 35 U.S.C. 119 and 120, priority under 35 U.S.C. 119 denied for failure to supply certified copy of the foreign application during pendency of the application that was filed within the twelve month period prescribed by 35 U.S.C. 119)).

Jump to MPEP SourceOrdering Certified CopiesCertified Copies of DocumentsPriority Document (Certified Copy)
Topic

Key Changes Under AIA

1 rules
StatutoryInformativeAlways
[mpep-2138-06-ee65e11ff31e5af0c680298d]
Key Changes Under AIA for Pre-AIA and Post-AIA Claims
Note:
This rule outlines the key changes under the America Invents Act (AIA) for patents with claims having both pre-AIA and post-AIA effective filing dates.

[Editor Note: This MPEP section has limited applicability to applications subject to examination under the first inventor to file (FITF) provisions of the AIA as set forth in 35 U.S.C. 100 (note). Patents and applications that contain (or contained at any time) at least one claim with a pre-AIA effective filing date (before March 16, 2013) and at least one claim with a post-AIA effective filing date (on or after March 16, 2013) are subject to the patentability requirements in AIA 35 U.S.C. 102 – 103 and subject to pre-AIA 35 U.S.C. 102(g).See MPEP § 2159 et seq.]

Jump to MPEP SourceKey Changes Under AIAAIA vs Pre-AIA PracticeDiligence Requirement
Topic

AIA Effective Dates

1 rules
StatutoryInformativeAlways
[mpep-2138-06-a588842e5268b0d2a8c03eba]
Patents with Pre-AIA and Post-AIA Claims Subject to Both AIA and Pre-AIA Requirements
Note:
Patents containing claims from both pre- and post-AIA filing dates must comply with both AIA and pre-AIA patentability requirements.

[Editor Note: This MPEP section has limited applicability to applications subject to examination under the first inventor to file (FITF) provisions of the AIA as set forth in 35 U.S.C. 100 (note). Patents and applications that contain (or contained at any time) at least one claim with a pre-AIA effective filing date (before March 16, 2013) and at least one claim with a post-AIA effective filing date (on or after March 16, 2013) are subject to the patentability requirements in AIA 35 U.S.C. 102 – 103 and subject to pre-AIA 35 U.S.C. 102(g).See MPEP § 2159 et seq.]

Jump to MPEP SourceAIA Effective DatesDetermining Whether Application Is AIA or Pre-AIAAIA Overview and Effective Dates
Topic

Diligence Requirement

1 rules
StatutoryInformativeAlways
[mpep-2138-06-a3ea4ab3d4c2b670362df5c3]
Reasonable Diligence Not Requiring Full Focus
Note:
The rule states that reasonable attorney-diligence and engineering-diligence under pre-AIA 35 U.S.C. 102(g) do not require inventors or their attorneys to drop all other work and focus solely on the invention.

The diligence of pre-AIA 35 U.S.C. 102(g) relates to reasonable “attorney-diligence” and “engineering-diligence” (Keizer v. Bradley, 270 F.2d 396, 397, 123 USPQ 215, 216 (CCPA 1959)), which does not require that “an inventor or his attorney … drop all other work and concentrate on the particular invention involved….” Emery v. Ronden, 188 USPQ 264, 268 (Bd. Pat. Inter. 1974).

Jump to MPEP SourceDiligence RequirementPre-AIA 102(g) – Prior Invention (MPEP 2138)
Topic

Design Patent Practice

1 rules
StatutoryProhibitedAlways
[mpep-2138-06-db007c0e499f0478a2f6ad59]
Requirement for Reasonable Diligence During Critical Period
Note:
The party must demonstrate reasonable efforts to reduce the invention to practice during the critical period from just prior to the opponent’s entry into the field, or provide acceptable excuses.

The period during which diligence is required must be accounted for by either affirmative acts or acceptable excuses. Rebstock v. Flouret, 191 USPQ 342, 345 (Bd. Pat. Inter. 1975); Rieser v. Williams, 255 F.2d 419, 423, 118 USPQ 96, 100 (CCPA 1958) (Being last to reduce to practice, party cannot prevail unless the party has shown that the party was first to conceive and that the party exercised reasonable diligence during the critical period from just prior to opponent’s entry into the field); Griffith v. Kanamaru, 816 F.2d 624, 2 USPQ2d 1361 (Fed. Cir. 1987) (Court generally reviewed cases on excuses for inactivity including vacation extended by ill health and daily job demands, and held lack of university funding and personnel are not acceptable excuses.); Litchfield v. Eigen, 535 F.2d 72, 190 USPQ 113 (CCPA 1976) (budgetary limits and availability of animals for testing not sufficiently described); Morway v. Bondi, 203 F.2d 741, 749, 97 USPQ 318, 323 (CCPA 1953) (voluntarily laying aside inventive concept in pursuit of other projects is generally not an acceptable excuse although there may be circumstances creating exceptions); Anderson v. Crowther, 152 USPQ 504, 512 (Bd. Pat. Inter. 1965) (preparation of routine periodic reports covering all accomplishments of the laboratory insufficient to show diligence); Wu v. Jucker, 167 USPQ 467, 472-73 (Bd. Pat. Inter. 1968) (applicant improperly allowed test data sheets to accumulate to a sufficient amount to justify interfering with equipment then in use on another project); Tucker v. Natta, 171 USPQ 494, 498 (Bd. Pat. Inter. 1971) (“[a]ctivity directed toward the reduction to practice of a genus does not establish, prima facie, diligence toward the reduction to practice of a species embraced by said genus”); Justus v. Appenzeller, 177 USPQ 332, 340-1 (Bd. Pat. Inter. 1971) (Although it is possible that patentee could have reduced the invention to practice in a shorter time by relying on stock items rather than by designing a particular piece of hardware, patentee exercised reasonable diligence to secure the required hardware to actually reduce the invention to practice. “[I]n deciding the question of diligence it is immaterial that the inventor may not have taken the expeditious course….”).

Jump to MPEP SourceDesign Patent PracticePTAB Contested Case Procedures

Citations

Primary topicCitation
AIA Effective Dates
Key Changes Under AIA
35 U.S.C. § 100
AIA Effective Dates
Key Changes Under AIA
35 U.S.C. § 102
AIA Effective Dates
Diligence Requirement
Key Changes Under AIA
35 U.S.C. § 102(g)
Ordering Certified Copies35 U.S.C. § 119
37 CFR § 1.131
AIA Effective Dates
Key Changes Under AIA
MPEP § 2159
Testimony Request ProceduresBroos v. Barton, 142 F.2d 690, 691, 61 USPQ 447, 448 (CCPA 1944)
Fitzgerald v. Arbib, 268 F.2d 763, 766, 122 USPQ 530, 532 (CCPA 1959)
Gould v. Schawlow, 363 F.2d 908, 919, 150 USPQ 634, 643 (CCPA 1966)
Design Patent PracticeGriffith v. Kanamaru, 816 F.2d 624, 2 USPQ2d 1361 (Fed. Cir. 1987)
Registration Number on SignatureHaskell v. Coleburne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982)
Testimony Request ProceduresHuelster v. Reiter, 168 F.2d 542, 78 USPQ 82 (CCPA 1948)
Ordering Certified CopiesHull v. Davenport, 90 F.2d 103, 105, 33 USPQ 506, 508 (CCPA 1937)
In re Harry, 333 F.2d 920, 923, 142 USPQ 164, 166 (CCPA 1964)
In re Mulder, 716 F.2d 1542, 1545, 219 USPQ 189, 193 (Fed. Cir. 1983)
Diligence RequirementKeizer v. Bradley, 270 F.2d 396, 397, 123 USPQ 215, 216 (CCPA 1959)
Kendall v. Searles, 173 F.2d 986, 993, 81 USPQ 363, 369 (CCPA 1949)
Design Patent PracticeLitchfield v. Eigen, 535 F.2d 72, 190 USPQ 113 (CCPA 1976)
Design Patent PracticeMorway v. Bondi, 203 F.2d 741, 749, 97 USPQ 318, 323 (CCPA 1953)
Testimony Request ProceduresNaber v. Cricchi, 567 F.2d 382, 384, 196 USPQ 294, 296 (CCPA 1977)
Design Patent PracticeRieser v. Williams, 255 F.2d 419, 423, 118 USPQ 96, 100 (CCPA 1958)
Registration Number on SignatureSee also Bey v. Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986)

Source Text from USPTO’s MPEP

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

BlueIron Last Updated: 2026-01-10