Calculating Patent Term Adjustment: Part 2

by Mintz Levin - Global IP Matters

This article is second in a series focusing on various issues related to Patent Term Adjustment for U.S. patent applications. While Part 1 is a general overview of how to calculate patent term adjustment (“PTA”), this article addresses how the filing of various papers during prosecution can affect PTA.  In particular, Requests for Continued Examination (RCEs), terminal disclaimers, and information disclosure statements (IDSs) can all cause adverse PTA effects if not carefully considered.

General Overview

Typically, U.S. patent term is 20 years from the earliest effective filing date, regardless of how long it takes the United States Patent and Trademark Office (“USPTO”) to examine and issue the patent.  In an effort to minimize the possibility of shortened patent term, Congress created the system of PTA, codified at 35 U.S.C. § 154(b), that allows, in certain circumstances, the effective patent term to be extended past 20 years from an application’s earliest effective filing date.  But as with many rules, there are exceptions.

Requests for Continued Examination

As explained in more detail in Part 1 of this blog series, 35 U.S.C. § 154(b)(1)(B) provides a guarantee of no more than a 3-year application pendency (the “3 Year Rule”).  However, an exception to the 3 Year Rule includes time consumed by an RCE.  It has been established that a patent application does not earn a “B” delay from the time an RCE is filed until a Notice of Allowance is issued, unless the USPTO actually resumes examination of the application after allowance.  Additionally, the submission of an RCE after a Notice of Allowance has been mailed will constitute a failure to engage in reasonable efforts to conclude examination, thereby resulting in Applicant delay.  Further discussion of PTA and RCEs can be found at Global IP Matters in relation to the Federal Circuit case Pfizer v. Lee and PTA rules implemented in response to Novartis v. Lee.

Example 1: B delay = 0 Days

Example 2: B delay = 1 Month

Example 3: B delay = 3 Months; Applicant Delay = 1 Month

Terminal Disclaimers

An applicant may file a terminal disclaimer to overcome a non-statutory double patenting rejection.  The standard USPTO terminal disclaimer form states that the disclaimed patent will not extend beyond the term of the prior patent.  While filing a terminal disclaimer to overcome such a rejection may seem innocuous, terminal disclaimers can nullify potential PTA for the disclaimed patent.  In particular, PTA cannot be used to extend the term of a patent beyond the expiration date set in a filed (and approved) terminal disclaimer.


  • Patent A is filed on January 1, 2000
  • Patent B is a continuation of Patent A
  • Terminal Disclaimer filed in Patent B over Patent A

Information Disclosure Statements

Inventors and those associated with filing or prosecuting patent applications as defined in 37 CFR § 1.56 have a duty to disclose to the USPTO information that is material to patentability.  This duty is deemed satisfied if such information is submitted to the USPTO via an IDS.  While 37 C.F.R. § 1.97 generally governs when and how IDSs may be submitted at different stages of prosecution, a “timely” filed IDS may not be so timely for purposes of PTA.

As set forth in 37 C.F.R. § 1.704, the filing of an IDS can result in a reduction of the PTA under several circumstances, for example when the IDS is filed after a response to an office action has been filed.  Therefore, the filing of an IDS under certain circumstances can trigger significant PTA reductions under 37 C.F.R. § 1.704.

Example: An RCE was filed on March 24, 2016, and no subsequent action taken by USPTO before the filing of an IDS.  Although the IDS filing is considered “timely” under 37 CFR § 1.97, the IDS filing constitutes a supplemental reply under 37 C.F.R. § 1.704, thereby resulting in an accrual of 364 days of Applicant delay.

The “30-Day Statement” Exception

A reduction of PTA can be avoided for an IDS filing by filing a statement under 37 C.F.R. § 1.704(d), which is provided below with emphasis added.  A statement under 37 C.F.R. § 1.704(d) (the “30-Day Statement”) should not be confused with the certification statements under 37 C.F.R. § 1.97(e).  Unlike the statements under 37 C.F.R. § 1.704(d), the statements under 37 C.F.R. § 1.97(e) have no effect on preventing PTA reduction.

 37 C.F.R. § 1.704(d) states

“A paper containing only an [IDS] … will not be considered a failure to engage in reasonable efforts to conclude prosecution … under paragraphs (c)(6), (c)(8), (c)(9), or (c)(10) of this section … if the paper … is accompanied by a statement that each item of information contained in the [IDS] … (i) Was first cited in any communication from a patent office in a counterpart [1] foreign or international application or [2] from the Office, and this communication was not received by any individual designated in 1.56(c) more than thirty days prior to the filing of the [IDS]…; or (ii) Is a communication that was issued by a [1] patent office in a counterpart foreign or international application or [2] by the Office, and this communication was not received by any individual designated in 1.56(c) more than thirty days prior to the filing of the information disclosure statement.”

Example: An RCE was filed on March 24, 2016, and no subsequent action taken by USPTO before the filing of an IDS with a 30-Day Statement.  Thus, no Applicant delay.


While the above discussion provides a general overview of certain factors that can affect PTA and how it is calculated, patentees are encouraged to consider when and whether to file various papers under every application’s particular circumstances and to verify PTA calculations according to the current rules and regulations of the USPTO.

[View source.]

DISCLAIMER: Because of the generality of this update, the information provided herein may not be applicable in all situations and should not be acted upon without specific legal advice based on particular situations.

© Mintz Levin - Global IP Matters | Attorney Advertising

Written by:

Mintz Levin - Global IP Matters

Mintz Levin - Global IP Matters on:

Readers' Choice 2017
Reporters on Deadline

"My best business intelligence, in one easy email…"

Your first step to building a free, personalized, morning email brief covering pertinent authors and topics on JD Supra:
Sign up using*

Already signed up? Log in here

*By using the service, you signify your acceptance of JD Supra's Privacy Policy.
Custom Email Digest
Privacy Policy (Updated: October 8, 2015):

JD Supra provides users with access to its legal industry publishing services (the "Service") through its website (the "Website") as well as through other sources. Our policies with regard to data collection and use of personal information of users of the Service, regardless of the manner in which users access the Service, and visitors to the Website are set forth in this statement ("Policy"). By using the Service, you signify your acceptance of this Policy.

Information Collection and Use by JD Supra

JD Supra collects users' names, companies, titles, e-mail address and industry. JD Supra also tracks the pages that users visit, logs IP addresses and aggregates non-personally identifiable user data and browser type. This data is gathered using cookies and other technologies.

The information and data collected is used to authenticate users and to send notifications relating to the Service, including email alerts to which users have subscribed; to manage the Service and Website, to improve the Service and to customize the user's experience. This information is also provided to the authors of the content to give them insight into their readership and help them to improve their content, so that it is most useful for our users.

JD Supra does not sell, rent or otherwise provide your details to third parties, other than to the authors of the content on JD Supra.

If you prefer not to enable cookies, you may change your browser settings to disable cookies; however, please note that rejecting cookies while visiting the Website may result in certain parts of the Website not operating correctly or as efficiently as if cookies were allowed.

Email Choice/Opt-out

Users who opt in to receive emails may choose to no longer receive e-mail updates and newsletters by selecting the "opt-out of future email" option in the email they receive from JD Supra or in their JD Supra account management screen.


JD Supra takes reasonable precautions to insure that user information is kept private. We restrict access to user information to those individuals who reasonably need access to perform their job functions, such as our third party email service, customer service personnel and technical staff. However, please note that no method of transmitting or storing data is completely secure and we cannot guarantee the security of user information. Unauthorized entry or use, hardware or software failure, and other factors may compromise the security of user information at any time.

If you have reason to believe that your interaction with us is no longer secure, you must immediately notify us of the problem by contacting us at In the unlikely event that we believe that the security of your user information in our possession or control may have been compromised, we may seek to notify you of that development and, if so, will endeavor to do so as promptly as practicable under the circumstances.

Sharing and Disclosure of Information JD Supra Collects

Except as otherwise described in this privacy statement, JD Supra will not disclose personal information to any third party unless we believe that disclosure is necessary to: (1) comply with applicable laws; (2) respond to governmental inquiries or requests; (3) comply with valid legal process; (4) protect the rights, privacy, safety or property of JD Supra, users of the Service, Website visitors or the public; (5) permit us to pursue available remedies or limit the damages that we may sustain; and (6) enforce our Terms & Conditions of Use.

In the event there is a change in the corporate structure of JD Supra such as, but not limited to, merger, consolidation, sale, liquidation or transfer of substantial assets, JD Supra may, in its sole discretion, transfer, sell or assign information collected on and through the Service to one or more affiliated or unaffiliated third parties.

Links to Other Websites

This Website and the Service may contain links to other websites. The operator of such other websites may collect information about you, including through cookies or other technologies. If you are using the Service through the Website and link to another site, you will leave the Website and this Policy will not apply to your use of and activity on those other sites. We encourage you to read the legal notices posted on those sites, including their privacy policies. We shall have no responsibility or liability for your visitation to, and the data collection and use practices of, such other sites. This Policy applies solely to the information collected in connection with your use of this Website and does not apply to any practices conducted offline or in connection with any other websites.

Changes in Our Privacy Policy

We reserve the right to change this Policy at any time. Please refer to the date at the top of this page to determine when this Policy was last revised. Any changes to our privacy policy will become effective upon posting of the revised policy on the Website. By continuing to use the Service or Website following such changes, you will be deemed to have agreed to such changes. If you do not agree with the terms of this Policy, as it may be amended from time to time, in whole or part, please do not continue using the Service or the Website.

Contacting JD Supra

If you have any questions about this privacy statement, the practices of this site, your dealings with this Web site, or if you would like to change any of the information you have provided to us, please contact us at:

- hide
*With LinkedIn, you don't need to create a separate login to manage your free JD Supra account, and we can make suggestions based on your needs and interests. We will not post anything on LinkedIn in your name. Or, sign up using your email address.