The PPH Program at the USPTO: Favorable Stats Don’t Alleviate Big Risks

By Kate Gaudry
October 30, 2019

“PPH requests appear to have been filed for less than 1% of U.S. applications. Why are applicants foregoing the program? While the program does not require payment of a fee per se, the author proposes that it is potentially associated with a very high cost.” 2006, the U.S. Patent and Trademark Office (USPTO) has participated in the Patent Prosecution Highway Pilot Program (the PPH Program). Generally, the program is designed to accelerate examination of a given patent application as a result of examination of a corresponding application at another PPH-participating patent office having reached a positive ruling more quickly. If an application is eligible for and accepted into the PPH Program, the USPTO expedites processing of the application. Examiners also have the benefit of drawing from another examiner’s assessment of corresponding claims.

Generally, existing data on the PPH Program has indicated that it is associated with increased allowance prospects and decreased examination times relative to non-PPH applications. However, the vast majority of this data is years old (e.g., from 2014). This article will briefly summarize the eligibility requirements for the program and present new data showing favorable allowance and pendency times. However, it will end with a warning: request entry to the PPH program in the United States at your own risk.

PPH Program Eligibility

In order for a U.S. application to be eligible for the PPH Pilot Program, four conditions must be met:

  1. U.S. Application and Corresponding Application have Same Earliest (Priority or Filing) Date

The U.S. application for which the PPH Request is being filed must have a same earliest date as the corresponding application. The earliest date is a priority date or filing date. The corresponding application is a national or regional application filed with another Global/IP5 PPH participating office of a Patent Cooperation Treaty (PCT) application for which one of the Global/IP5 PPH participating offices was the International Searching Authority (ISA) or International Preliminary Examining Authority (IPEA).

  1. Corresponding Application Has One or More Allowable/Patentable Claims

The examining office/authority that examined the corresponding application must have found at least one claim to be allowable or patentable. If the corresponding application is a PCT application, this requirement is satisfied if the ISA or IPEA found that at least one claim to be was novel, was inventive and has industrial applicability.

  1. Claim(s) Sufficiently Correspond

All claims in the U.S. application must sufficiently correspond to an allowable/patentable claim of the corresponding application. “Sufficiently correspond” means that the U.S. claim is of the same or similar scope as an allowable/patentable claim in the corresponding application. The USPTO Implementation Guidelines of the PPH Pilot Program state: “A claim in the U.S. application that is narrower in scope than the claims indicated as allowable/patentable … will sufficiently correspond if presented as a claim dependent upon a claim that is of the same or similar scope as a claim indicated as allowable/patentable”.

  1. Examination of U.S. Application Has Not Yet Begun

A PPH request must be filed in the United States before substantive examination of the U.S. application has begun. Thus, the request must be filed prior to issuance of any U.S. office action.

PPH Program: Higher Allowance Rates and Fewer Office Actions

To empirically assess the PPH program, the author requested data from the USPTO that indicated the allowance rates and average number of office actions per patent for (1) all utility applications having reached a final disposition in fiscal year 2019; and (2) all utility applications for which a PPH request was granted and for which a final disposition was reached in fiscal year 2019. Data was further separated by technology center.

Figure 1 shows that, for fiscal year 2019 and across all technology centers, the allowance rate of the PPH applications exceeded the allowance rate of the broader data set of applications. Overall, the allowance rate across all utility patent applications for fiscal year 2019 was 74%, while the allowance rate for utility patent applications in fiscal year 2019 for which a PPH request had been granted was 84%.


Figure 1

Figure 2 shows that, for fiscal year 2019 and across all technology centers, the average number of office actions per patent for PPH applications was lower than the average number of office actions per patent for the broader data set of applications. Overall, the average number of office actions per utility patent issued in fiscal year 2019 was 1.7, while the average number of office actions per patent issued in fiscal year 2019 and having been accepted into the PPH program was 1.5.


Figure 2


Notably, the applications that were eligible for the PPH Program may have been better positioned to receive allowances and efficient examination as compared to other applications. First, the applicants of the PPH applications had determined that the technology at issue was sufficiently important to foreign file. This may suggest that the applicants’ invention was particularly important/unique, which may generally increase the chances of securing a patent. Further, the foreign filing suggests that the applicants had the resources for foreign filing. Having resources available for patenting may indicate that the applicant could also access high-quality in-house lawyers or outside counsel for patent drafting and prosecution. Finally, the PPH request is frequently accompanied by a preliminary amendment in which the claims are narrowed to match allowed claims. Thus, an overall initial scope of claims of PPH applications may be narrower than overall initial claim scopes of non-PPH applications.

Proceed at Your Own Risk (For Now at Least)

The above data indicates that participating in the PPH Program is associated with applicant-favorable statistics of higher allowance rates and fewer rejections. While self-selection issues may apply to these statistics, the PPH program is free, so one may consider that there is little harm in trying this program.

Yet, interestingly, relatively few PPH requests have been filed at the USPTO. From the inception of the PPH program in 2006 through the end of Fiscal Year 2018, approximately 55,000 PPH requests have been filed at the USPTO. Meanwhile, the total number of utility patent applications filed between 2006 and 2018 was 6,824,912. Thus, PPH requests appear to have been filed for less than 1% of U.S. applications.

Why are applicants foregoing the program? While the program does not require payment of a fee per se, the author proposes that it is potentially associated with a very high cost. Namely, the PPH Program as it is currently implemented severely limits amendment opportunities, to the point that the USPTO has proposed abandoning an application and filing a continuation in certain circumstances.

If a USPTO examiner does not believe that the claims correspond to a PPH request, the examiner is to generally proceed as normal and issue an office action.  In this office action, the examiner may cite new art. The applicant can reply via an amendment, but importantly, the USPTO Implementation Guidelines of the PPH Pilot Program state:

Any claims amended or added after the grant of the request for participation in the Global/IP5 PPH pilot program must sufficiently correspond to one or more allowable/patentable claims in the OEE application. The applicant is required to submit, along with the amendment, a statement certifying that the amended or newly added claims sufficiently correspond to the allowable/patentable claims in the OEE application. If the certification statement is omitted, the amendment will not be entered and will be treated as a non-responsive reply.

These Guidelines specify that a claim sufficiently corresponds when it is of the same or similar scope as an allowable/patentable claim in the corresponding application. Further, if a U.S. claim is of narrower scope than the claim indicated as being allowable/patentable, it is to be presented as a dependent claim and can be integrated into an independent claim if an examiner has indicated that the claim would be allowable if rewritten in independent form. (See the Q&A for Questions 34-35 of the USPTO PPH FAQs.)

The author has spoken to several USPTO employees about these guidelines. One interpreted the Guidelines as indicating that no amendment could be made subsequent to any Preliminary Amendment filed with the PPH Request (at which time a dependent claim could include a narrower scope than what was found to be allowable/patentable for a corresponding application). Another interpreted the Guidelines as indicating that an amendment could introduce a narrowing limitation only via a new dependent claim (which could be incorporated into an independent claim if it were found to be allowable).

Thus, one risk of the PPH Program is that a USPTO examiner may assert that absolutely no amendment is compliant with the program. Even if a USPTO examiner does believe that it is possible to introduce a narrowing limitation, this would be introduced in an inefficient manner, as it would very likely require an additional amendment to integrate the new limitation with the independent claim if it were found to be allowable.

But most alarming to the author is that any amendment must be accompanied with a certification that the new claim(s) “sufficiently correspond” (i.e., is of the same or similar scope) as an allowable/patentable claim. If such certification is omitted, the amendment will be treated as a non-responsive reply. And once an application is in the PPH Program, there is no escaping it. (Q&A 24 of the USPTO PPH FAQs: “Is it possible to withdraw from the PPH program after I receive a granted PPH request? No. … If participation in the PPH program is no longer desired, applicant may wish to consider filing a continuing application.”)

Thus, suppose that the USPTO examiner identifies (or the practitioner spots) a potentially valid indefiniteness, written-description or enablement issue. Perhaps the issue would be rather simple to address with an amendment. However, unless the applicant is willing to certify that that amendment does not expand the scope of the claim, it would be a non-compliant amendment. (Consider how such certification may be problematic if an applicant wishes to replace “detecting that a device is in use” with “detecting that a device is receiving power”). Alternatively, suppose that a USPTO examiner cites a new reference and that the applicant has identified an adjusted scope that would distinguish the reference. Once again, unless the applicant is comfortable certifying that the amendment only narrows the claim, an amendment would be non-compliant.

The USPTO Should Remove These Risks

In an over-simplified instance, one may equate underlined text in an amendment to narrowing language and stricken-through text to broadening language. Many of the amendments prepared by the author would then only include narrowing language (or neither narrowing or broadening language). However, a substantial portion include potentially broadening language. That portion is just too sizable for the author to feel comfortable submitting PPH requests to the USPTO, despite the program’s generally favorable statistics.

Should the USPTO relax or remove the severe amendment constraints, the PPH Program would seem to be a mutually beneficial program for the USPTO and for applicants.

Image Source: Deposit Photos
Image ID: 12202808
Copyright: Krivosheevv 

The Author

Kate Gaudry

Kate Gaudry , Ph.D., is a partner at Kilpatrick Townsend & Stockton LLP. She focuses her practice on patent prosecution, with an emphasis on software, computer systems, and quantitative biology technologies. Dr. Gaudry also routinely performs statistical analysis of clients’ patent portfolios to identify effective prosecution strategies. Her research and data focus was recognized when she was one of five attorneys across all practice areas to be selected for LexMachina’s and Law360’s Data-Driven Lawyer award in its inaugural year of 2018.

For more information, or to contact Dr. Gaudry, please visit her firm profile page.

Warning & Disclaimer: The pages, articles and comments on do not constitute legal advice, nor do they create any attorney-client relationship. The articles published express the personal opinion and views of the author as of the time of publication and should not be attributed to the author’s employer, clients or the sponsors of Read more.

Discuss this

There are currently 6 Comments comments.

  1. Anon October 30, 2019 5:24 pm

    Not seeing the “dread” in the existing pathway out of filing a Continuation.

    Lacking that dread, I do not see the fire here that the author sees.

    There may be another reason why the participation is so minimal — lacking a workable out is not that reason.

  2. Pro Say October 30, 2019 6:38 pm

    Ugh. Given the material drawbacks and risks (thanks Kate), it’s more a wonder why anywhere near 55,000 requests were made than why only less than 1% of applicants make use of PPH.

    Indeed, I could see where having to certifying that the amended or newly added claims sufficiently correspond to the allowable/patentable claims in the OEE application could by itself cause problems in any later litigation/s; including potentially being accused of committing fraud on the Patent Office (with a potentially corresponding invalidation of the entire patent/s family).

    I’ve never utilized PPH and never will.

  3. Lost In Norway October 31, 2019 5:22 am

    I would like to thank the author for their analysis. I have also wondered why PPH is not used as often in the US when compared to other places in the world.

    While a continuation is not the most difficult of exit strategies, it does cost the client more money. I have to agree with Anon@1 that there must be other reasons for a lack of participation.

    Did your analysis show that examination was in fact started earlier with PPH? I know that asking for accelerated examination due to age can actually lead to a slower first office action.

  4. MaxDrei October 31, 2019 6:56 am

    My experience is in prosecuting cases of US origin at the EPO. I’m not at all surprised by the disinclination of Applicants to use the PPH. They know (perhaps not as well as I do, but well enough) that claims which are optimal for RoW are often not fit for purpose in the USA. It works the other way too. Claims for the USA are often sub-optimal everywhere else.

    BTW, are there any stats that show how much the PPH is used in between other jurisdiction pairs, in particular the EPO with i) Japan or ii) China or iii) Korea? I ask because if a single set of claims can be optimal for all these jurisdictions usage of PPH should, logically, be higher.

  5. Lost In Norway November 1, 2019 7:06 am


    My experience with PPH has been that it is highly effective in any country that is going to rubber stamp a ruling from another patent office. That is never going to be between the IP5. Many places around the world will approve claims granted by the EPO without a second through. This can be particularly advantageous for PCT applications if a positive patentability opinion is received using the EPO as the ISA.

    In places where there is no rubber stamping, I have found it to have the same problems as the author describes. Also most countries have ways to request an accelerated examination that is not PPH (like PACE at the EPO) and is usually free.

  6. Night Writer November 1, 2019 1:20 pm

    So I guess the statistic that would good to see is how many times has an applicant used PPH with a favorable IPRP and had an office action that requires claim amendments?