MPEP § 2755.01 — Interim Extension of Patent Term During the Processing of the Application (Annotated Rules)

§2755.01 Interim Extension of Patent Term During the Processing of the Application

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

This page consolidates and annotates all enforceable requirements under MPEP § 2755.01, 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.

Interim Extension of Patent Term During the Processing of the Application

This section addresses Interim Extension of Patent Term During the Processing of the Application. Primary authority: 35 U.S.C. 156, 35 U.S.C. 156(e)(2), and 35 U.S.C. 156(c)(4). Contains: 1 requirement, 4 guidance statements, 4 permissions, and 9 other statements.

Key Rules

Topic

PTE Application Requirements

7 rules
StatutoryRecommendedAlways
[mpep-2755-01-daacea2392698c3ef3e2fe15]
Request for Interim Patent Term Extension Before Expiration
Note:
An applicant may request interim extensions of up to one year each before the final determination on a patent extension application, but must file at least three months prior to the expiration date.

An applicant who has filed a formal application for extension in compliance with § 1.740 may request one or more interim extensions for periods of up to one year each pending a final determination on the application pursuant to § 1.750. Any such request should be filed at least three months prior to the expiration date of the patent. The Director may issue interim extensions, without a request by the applicant, for periods of up to one year each until a final determination is made. The patent owner or agent will be notified when an interim extension is granted and notice of the extension will be published in the Official Gazette of the United States Patent and Trademark Office. The notice will be recorded in the official file of the patent and will be considered as part of the original patent. In no event will the interim extensions granted under this section be longer than the maximum period for extension to which the applicant would be eligible.

Jump to MPEP Source · 37 CFR 1.740PTE Application RequirementsPTE Determination ProcedureDetermining Expiration Date
StatutoryPermittedAlways
[mpep-2755-01-e79cef808052c09cb6481321]
Interim Patent Term Extension During Processing
Note:
If a patent's term will expire before a final extension decision, the Director may grant an interim extension of up to one year pending a final decision on the application for extension.

If the original term of the patent for which extension is sought will expire before a final decision to issue a certificate of extension can be made, and a determination is made that the patent is eligible for extension, 35 U.S.C. 156 provides that the Director may issue an interim extension of the patent term for up to one year pending a final decision on the application for extension. Should additional time be necessary, additional interim extensions of up to one year may be granted by the Director. The length of any interim extension is discretionary with the Director so long as it is for one year or less. Its length should be set to provide time for completion of any outstanding requirements. See In re Reckitt & Colman Products Ltd., 230 USPQ 369, 372 (Comm’r Pat. & Tm. 1986). The Director may issue an interim extension under 35 U.S.C. 156(e)(2) with or without a request from the applicant. However, it is a best practice for the applicant for term extension to track the expiration dates of any patents for which extension has been sought and timely file a request for interim extension under 37 CFR 1.760 in order for the Office to timely grant an interim extension under 35 U.S.C. 156(e)(2).

Jump to MPEP Source · 37 CFR 1.760PTE Application RequirementsPTE Determination ProcedurePTE Eligibility Requirements
StatutoryRecommendedAlways
[mpep-2755-01-6bb052f36895d4378e836b4e]
Additional Interim Extensions May Be Granted
Note:
The Director may grant additional interim extensions of up to one year if the original term of a patent expires before a final decision on extension can be made.

If the original term of the patent for which extension is sought will expire before a final decision to issue a certificate of extension can be made, and a determination is made that the patent is eligible for extension, 35 U.S.C. 156 provides that the Director may issue an interim extension of the patent term for up to one year pending a final decision on the application for extension. Should additional time be necessary, additional interim extensions of up to one year may be granted by the Director. The length of any interim extension is discretionary with the Director so long as it is for one year or less. Its length should be set to provide time for completion of any outstanding requirements. See In re Reckitt & Colman Products Ltd., 230 USPQ 369, 372 (Comm’r Pat. & Tm. 1986). The Director may issue an interim extension under 35 U.S.C. 156(e)(2) with or without a request from the applicant. However, it is a best practice for the applicant for term extension to track the expiration dates of any patents for which extension has been sought and timely file a request for interim extension under 37 CFR 1.760 in order for the Office to timely grant an interim extension under 35 U.S.C. 156(e)(2).

Jump to MPEP Source · 37 CFR 1.760PTE Application RequirementsPTE Determination ProcedurePTE Eligibility Requirements
StatutoryInformativeAlways
[mpep-2755-01-29602162a1c92005848aa725]
Interim Extension of Patent Term Is Discretionary Up to One Year
Note:
The Director may grant interim extensions for up to one year, at their discretion, while processing a patent extension application.

If the original term of the patent for which extension is sought will expire before a final decision to issue a certificate of extension can be made, and a determination is made that the patent is eligible for extension, 35 U.S.C. 156 provides that the Director may issue an interim extension of the patent term for up to one year pending a final decision on the application for extension. Should additional time be necessary, additional interim extensions of up to one year may be granted by the Director. The length of any interim extension is discretionary with the Director so long as it is for one year or less. Its length should be set to provide time for completion of any outstanding requirements. See In re Reckitt & Colman Products Ltd., 230 USPQ 369, 372 (Comm’r Pat. & Tm. 1986). The Director may issue an interim extension under 35 U.S.C. 156(e)(2) with or without a request from the applicant. However, it is a best practice for the applicant for term extension to track the expiration dates of any patents for which extension has been sought and timely file a request for interim extension under 37 CFR 1.760 in order for the Office to timely grant an interim extension under 35 U.S.C. 156(e)(2).

Jump to MPEP Source · 37 CFR 1.760PTE Application RequirementsPTE Determination ProcedurePTE Eligibility Requirements
StatutoryRecommendedAlways
[mpep-2755-01-f476577324d796a95ac31750]
Interim Extension Must Provide Time for Completion of Requirements
Note:
The Director may issue interim extensions up to one year to allow completion of any outstanding requirements before a final patent extension decision.

If the original term of the patent for which extension is sought will expire before a final decision to issue a certificate of extension can be made, and a determination is made that the patent is eligible for extension, 35 U.S.C. 156 provides that the Director may issue an interim extension of the patent term for up to one year pending a final decision on the application for extension. Should additional time be necessary, additional interim extensions of up to one year may be granted by the Director. The length of any interim extension is discretionary with the Director so long as it is for one year or less. Its length should be set to provide time for completion of any outstanding requirements. See In re Reckitt & Colman Products Ltd., 230 USPQ 369, 372 (Comm’r Pat. & Tm. 1986). The Director may issue an interim extension under 35 U.S.C. 156(e)(2) with or without a request from the applicant. However, it is a best practice for the applicant for term extension to track the expiration dates of any patents for which extension has been sought and timely file a request for interim extension under 37 CFR 1.760 in order for the Office to timely grant an interim extension under 35 U.S.C. 156(e)(2).

Jump to MPEP Source · 37 CFR 1.760PTE Application RequirementsPTE Determination ProcedurePTE Eligibility Requirements
StatutoryInformativeAlways
[mpep-2755-01-c8d788477875a45266cb3df7]
Interim Patent Term Extension During Processing
Note:
The Director may issue interim extensions of up to one year while processing a patent term extension application, ensuring time for completion of any outstanding requirements.

If the original term of the patent for which extension is sought will expire before a final decision to issue a certificate of extension can be made, and a determination is made that the patent is eligible for extension, 35 U.S.C. 156 provides that the Director may issue an interim extension of the patent term for up to one year pending a final decision on the application for extension. Should additional time be necessary, additional interim extensions of up to one year may be granted by the Director. The length of any interim extension is discretionary with the Director so long as it is for one year or less. Its length should be set to provide time for completion of any outstanding requirements. See In re Reckitt & Colman Products Ltd., 230 USPQ 369, 372 (Comm’r Pat. & Tm. 1986). The Director may issue an interim extension under 35 U.S.C. 156(e)(2) with or without a request from the applicant. However, it is a best practice for the applicant for term extension to track the expiration dates of any patents for which extension has been sought and timely file a request for interim extension under 37 CFR 1.760 in order for the Office to timely grant an interim extension under 35 U.S.C. 156(e)(2).

Jump to MPEP Source · 37 CFR 1.760PTE Application RequirementsPTE Determination ProcedurePTE Eligibility Requirements
StatutoryRequiredAlways
[mpep-2755-01-b640d331b72168efa1949ff1]
Interim Extension Before Patent Expiration
Note:
An application for an interim extension must be filed before the patent expires to consider requests made within a shorter period.

While 37 CFR 1.760 provides that a request for an interim extension by the applicant under 35 U.S.C. 156(e)(2) “should” be filed three months prior to the expiration of the patent, this time frame is not mandatory. Any request filed within a shorter period of time will be considered, upon a proper showing, where it is not possible to make an earlier request. However, for an interim extension to be granted, the application for extension, in compliance with 37 CFR 1.741, must have been filed prior to the expiration date of the patent. In no event will an interim extension be granted for a period of patent term extension longer than the period of extension to which the patent would be eligible.

Jump to MPEP Source · 37 CFR 1.760PTE Application RequirementsPTE Determination ProcedureDetermining Expiration Date
Topic

PTE Determination Procedure

7 rules
StatutoryPermittedAlways
[mpep-2755-01-af28df8eda2134e7fbb1aaa3]
Director May Issue Interim Extensions Without Request
Note:
The Director can grant interim extensions of up to one year each without an applicant's request until a final determination is made.

An applicant who has filed a formal application for extension in compliance with § 1.740 may request one or more interim extensions for periods of up to one year each pending a final determination on the application pursuant to § 1.750. Any such request should be filed at least three months prior to the expiration date of the patent. The Director may issue interim extensions, without a request by the applicant, for periods of up to one year each until a final determination is made. The patent owner or agent will be notified when an interim extension is granted and notice of the extension will be published in the Official Gazette of the United States Patent and Trademark Office. The notice will be recorded in the official file of the patent and will be considered as part of the original patent. In no event will the interim extensions granted under this section be longer than the maximum period for extension to which the applicant would be eligible.

Jump to MPEP Source · 37 CFR 1.740PTE Determination ProcedurePatent Term ExtensionPatent Term
StatutoryInformativeAlways
[mpep-2755-01-a693888e698e9a3efb4ae67a]
Interim Extensions Cannot Exceed Maximum Eligible Period
Note:
The interim extensions granted cannot be longer than the maximum period for which an applicant would be eligible under the patent term extension rules.

An applicant who has filed a formal application for extension in compliance with § 1.740 may request one or more interim extensions for periods of up to one year each pending a final determination on the application pursuant to § 1.750. Any such request should be filed at least three months prior to the expiration date of the patent. The Director may issue interim extensions, without a request by the applicant, for periods of up to one year each until a final determination is made. The patent owner or agent will be notified when an interim extension is granted and notice of the extension will be published in the Official Gazette of the United States Patent and Trademark Office. The notice will be recorded in the official file of the patent and will be considered as part of the original patent. In no event will the interim extensions granted under this section be longer than the maximum period for extension to which the applicant would be eligible.

Jump to MPEP Source · 37 CFR 1.740PTE Determination ProcedurePTE Eligibility RequirementsPatent Eligibility
StatutoryInformativeAlways
[mpep-2755-01-51c12f9edea7ea2f8f965762]
No Interim Extension for Non-Eligible PTE Patent
Note:
If a patent is determined not eligible for patent term extension, an interim extension of the patent term is not warranted under 35 U.S.C. 156(e)(2).

Where a determination is made that the patent is not eligible for patent term extension, an interim extension of the patent term is not warranted under 35 U.S.C. 156(e)(2). See In re Alcon Laboratories Inc., 13 USPQ2d 1115, 1123 (Comm’r. Pat.& Tm. 1989).

Jump to MPEP Source · 37 CFR 1.760PTE Determination ProcedurePTE Eligibility RequirementsPatent Term Extension
StatutoryInformativeAlways
[mpep-2755-01-6c5a70df5734e1004a0699a1]
No Interim Extension for Invalid PTE
Note:
If a patent is not eligible for patent term extension, an interim extension of the patent term is not warranted.

Where a determination is made that the patent is not eligible for patent term extension, an interim extension of the patent term is not warranted under 35 U.S.C. 156(e)(2). See In re Alcon Laboratories Inc., 13 USPQ2d 1115, 1123 (Comm’r. Pat.& Tm. 1989).

Jump to MPEP Source · 37 CFR 1.760PTE Determination ProcedurePTE Eligibility RequirementsPatent Term Extension
StatutoryPermittedAlways
[mpep-2755-01-726818fcf0bbfaf776f91c3d]
Interim Extension May Be Vacated If Patent Not Eligible for PTE
Note:
If an interim extension has been granted but the patent is later found ineligible for patent term extension, the interim extension may be vacated from the beginning.

Where an interim extension has been granted and it is subsequently determined that the patent is not eligible for patent term extension, the interim extension may be vacated ab initio as ineligible under 35 U.S.C. 156(e)(2). See In re Reckitt & Colman Products Ltd., 230 USPQ at 370.

Jump to MPEP Source · 37 CFR 1.760PTE Determination ProcedurePTE Eligibility RequirementsPatent Term Extension
StatutoryInformativeAlways
[mpep-2755-01-fc980af7ca941c96f85b9313]
Vacating Interim Patent Term Extensions
Note:
If a patent is found ineligible for term extension after an interim extension, the initial extension may be vacated.

Where an interim extension has been granted and it is subsequently determined that the patent is not eligible for patent term extension, the interim extension may be vacated ab initio as ineligible under 35 U.S.C. 156(e)(2). See In re Reckitt & Colman Products Ltd., 230 USPQ at 370.

Jump to MPEP Source · 37 CFR 1.760PTE Determination ProcedurePTE Eligibility RequirementsPatent Term Extension
StatutoryInformativeAlways
[mpep-2755-01-b658113921e937aa7f262989]
Interim Extension Cannot Extend Patent Term Beyond Eligible Period
Note:
An interim extension cannot be granted for a period longer than the patent's eligible extension period.

While 37 CFR 1.760 provides that a request for an interim extension by the applicant under 35 U.S.C. 156(e)(2) “should” be filed three months prior to the expiration of the patent, this time frame is not mandatory. Any request filed within a shorter period of time will be considered, upon a proper showing, where it is not possible to make an earlier request. However, for an interim extension to be granted, the application for extension, in compliance with 37 CFR 1.741, must have been filed prior to the expiration date of the patent. In no event will an interim extension be granted for a period of patent term extension longer than the period of extension to which the patent would be eligible.

Jump to MPEP Source · 37 CFR 1.760PTE Determination ProcedurePTE Eligibility RequirementsPatent Term Extension
Topic

Patent Term Extension

5 rules
StatutoryInformativeAlways
[mpep-2755-01-98bf4ff75e88495e5494a091]
Patent Owner Notified of Interim Extensions
Note:
The patent owner or agent is informed when an interim extension is granted, and this information is published in the Official Gazette.

An applicant who has filed a formal application for extension in compliance with § 1.740 may request one or more interim extensions for periods of up to one year each pending a final determination on the application pursuant to § 1.750. Any such request should be filed at least three months prior to the expiration date of the patent. The Director may issue interim extensions, without a request by the applicant, for periods of up to one year each until a final determination is made. The patent owner or agent will be notified when an interim extension is granted and notice of the extension will be published in the Official Gazette of the United States Patent and Trademark Office. The notice will be recorded in the official file of the patent and will be considered as part of the original patent. In no event will the interim extensions granted under this section be longer than the maximum period for extension to which the applicant would be eligible.

Jump to MPEP Source · 37 CFR 1.740Patent Term ExtensionPatent TermPTE Application Requirements
StatutoryInformativeAlways
[mpep-2755-01-e3b3ec6c9e817e7bb23424ed]
Notice of Interim Extension Is Part of Original Patent
Note:
The notice informing of an interim extension will be recorded in the official patent file and considered part of the original patent.

An applicant who has filed a formal application for extension in compliance with § 1.740 may request one or more interim extensions for periods of up to one year each pending a final determination on the application pursuant to § 1.750. Any such request should be filed at least three months prior to the expiration date of the patent. The Director may issue interim extensions, without a request by the applicant, for periods of up to one year each until a final determination is made. The patent owner or agent will be notified when an interim extension is granted and notice of the extension will be published in the Official Gazette of the United States Patent and Trademark Office. The notice will be recorded in the official file of the patent and will be considered as part of the original patent. In no event will the interim extensions granted under this section be longer than the maximum period for extension to which the applicant would be eligible.

Jump to MPEP Source · 37 CFR 1.740Patent Term ExtensionPatent TermPTE Application Requirements
StatutoryPermittedAlways
[mpep-2755-01-dc5ecb282c96b3193a2d6b2e]
Interim Patent Term Extension Best Practice
Note:
Applicants should track patent expiration dates and timely request interim extensions to ensure timely issuance of an extension under 35 U.S.C. 156(e)(2).

If the original term of the patent for which extension is sought will expire before a final decision to issue a certificate of extension can be made, and a determination is made that the patent is eligible for extension, 35 U.S.C. 156 provides that the Director may issue an interim extension of the patent term for up to one year pending a final decision on the application for extension. Should additional time be necessary, additional interim extensions of up to one year may be granted by the Director. The length of any interim extension is discretionary with the Director so long as it is for one year or less. Its length should be set to provide time for completion of any outstanding requirements. See In re Reckitt & Colman Products Ltd., 230 USPQ 369, 372 (Comm’r Pat. & Tm. 1986). The Director may issue an interim extension under 35 U.S.C. 156(e)(2) with or without a request from the applicant. However, it is a best practice for the applicant for term extension to track the expiration dates of any patents for which extension has been sought and timely file a request for interim extension under 37 CFR 1.760 in order for the Office to timely grant an interim extension under 35 U.S.C. 156(e)(2).

Jump to MPEP Source · 37 CFR 1.760Patent Term ExtensionPatent TermPTE Application Requirements
StatutoryRecommendedAlways
[mpep-2755-01-58a88e903d1bff431adaa763]
Interim Extension Not Mandatory Within Three Months
Note:
A request for an interim extension under 35 U.S.C. 156(e)(2) does not need to be filed exactly three months before patent expiration, but must still be filed prior to the expiration date.

While 37 CFR 1.760 provides that a request for an interim extension by the applicant under 35 U.S.C. 156(e)(2) “should” be filed three months prior to the expiration of the patent, this time frame is not mandatory. Any request filed within a shorter period of time will be considered, upon a proper showing, where it is not possible to make an earlier request. However, for an interim extension to be granted, the application for extension, in compliance with 37 CFR 1.741, must have been filed prior to the expiration date of the patent. In no event will an interim extension be granted for a period of patent term extension longer than the period of extension to which the patent would be eligible.

Jump to MPEP Source · 37 CFR 1.760Patent Term ExtensionPatent Term ExpirationPatent Term
StatutoryInformativeAlways
[mpep-2755-01-e281d150e84e11958fe71ec7]
Interim Extensions Distinguished from Final Certificates
Note:
This rule distinguishes interim extensions granted under 35 U.S.C. 156(e)(2) or 156(d)(5) from a final certificate of extension, as added in 1993 by section 5 of Public Law 103-179.

In circumstances where extensions of multiple patents have been sought based on a single regulatory review period as per 37 CFR 1.785, multiple interim extensions under 35 U.S.C. 156(e)(2) are permitted. This is possible because 35 U.S.C. 156(c)(4) recites the prohibition that, “in no event shall more than one patent be extended under subsection (e)(1) for the same regulatory review period for any product.” The language “under subsection (e)(1) ” refers to the certificate of extension only. This language was added in 1993 by section 5 of Public Law 103-179, which was the same time when the interim extension provisions of 35 U.S.C. 156(d)(5) were added, so as to distinguish a final certificate of extension from interim extensions granted under either 35 U.S.C. 156(e)(2) or 35 U.S.C. 156(d)(5).

Jump to MPEP Source · 37 CFR 1.785Patent Term ExtensionPatent TermPTE Calculation
Topic

PTE Calculation

1 rules
StatutoryRequiredAlways
[mpep-2755-01-c65fc199c35ce4d2749e4565]
Multiple Interim Extensions Permitted for Same Regulatory Review Period
Note:
Allows multiple patents to seek interim extensions based on a single regulatory review period despite the prohibition against more than one final extension.

In circumstances where extensions of multiple patents have been sought based on a single regulatory review period as per 37 CFR 1.785, multiple interim extensions under 35 U.S.C. 156(e)(2) are permitted. This is possible because 35 U.S.C. 156(c)(4) recites the prohibition that, “in no event shall more than one patent be extended under subsection (e)(1) for the same regulatory review period for any product.” The language “under subsection (e)(1) ” refers to the certificate of extension only. This language was added in 1993 by section 5 of Public Law 103-179, which was the same time when the interim extension provisions of 35 U.S.C. 156(d)(5) were added, so as to distinguish a final certificate of extension from interim extensions granted under either 35 U.S.C. 156(e)(2) or 35 U.S.C. 156(d)(5).

Jump to MPEP Source · 37 CFR 1.785PTE CalculationPatent Term ExtensionPatent Term
Topic

Patent Term

1 rules
StatutoryInformativeAlways
[mpep-2755-01-3e6ff72faeea1ed1dddffd5a]
Certificate of Extension Refers Only to Final Certificate
Note:
The language 'under subsection (e)(1)' refers exclusively to the final certificate of extension, distinguishing it from interim extensions granted under other provisions.

In circumstances where extensions of multiple patents have been sought based on a single regulatory review period as per 37 CFR 1.785, multiple interim extensions under 35 U.S.C. 156(e)(2) are permitted. This is possible because 35 U.S.C. 156(c)(4) recites the prohibition that, “in no event shall more than one patent be extended under subsection (e)(1) for the same regulatory review period for any product.” The language “under subsection (e)(1) ” refers to the certificate of extension only. This language was added in 1993 by section 5 of Public Law 103-179, which was the same time when the interim extension provisions of 35 U.S.C. 156(d)(5) were added, so as to distinguish a final certificate of extension from interim extensions granted under either 35 U.S.C. 156(e)(2) or 35 U.S.C. 156(d)(5).

Jump to MPEP Source · 37 CFR 1.785Patent TermPTE CalculationPatent Term Extension

Citations

Primary topicCitation
PTE Application Requirements
Patent Term Extension
35 U.S.C. § 156
PTE Calculation
Patent Term
Patent Term Extension
35 U.S.C. § 156(c)(4)
PTE Calculation
Patent Term
Patent Term Extension
35 U.S.C. § 156(d)(5)
PTE Application Requirements
PTE Calculation
PTE Determination Procedure
Patent Term
Patent Term Extension
35 U.S.C. § 156(e)(2)
PTE Application Requirements
PTE Determination Procedure
Patent Term Extension
37 CFR § 1.740
PTE Application Requirements
PTE Determination Procedure
Patent Term Extension
37 CFR § 1.741
PTE Application Requirements
PTE Determination Procedure
Patent Term Extension
37 CFR § 1.750
PTE Application Requirements
PTE Determination Procedure
Patent Term Extension
37 CFR § 1.760
PTE Calculation
Patent Term
Patent Term Extension
37 CFR § 1.785

Source Text from USPTO’s MPEP

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BlueIron Last Updated: 2025-12-31