Understanding U.S. Patent Prosecution

The journey from conceiving of an idea through turning that idea into an invention through ultimately receiving a patent for an invention can be daunting. It is a long process, with ups and downs along the way, and one that unfortunately can get expensive. Obtaining filing a patent application and obtaining a patent can be an extremely worthwhile endeavor, but it does require determination to see the project through to the end. Those who give up easily do not tend to make good inventors, and rarely do they become patented inventors.

The journey to a patent begins much before actually filing the patent application. We have many articles on the pre-application idea and invention phase of your quest. This article, however, provides an overview of the patent application and prosecution process (i.e., working with the patent examiner). For more on the pre-application phase please see Invention to Patent 101 – Everything You Need to Know to Get Started.


In order to obtain a patent in the U.S. you must first file a patent application. For an applicant to be granted a filing date for a non-provisional patent application, the United States Patent and Trademark Office (“USPTO”) requires an applicant, at a bare minimum, to submit a specification with or without claims. See 37 C.F.R. § 1.53(b), however, best practice is still to file an application that has high quality drawings at the time of filing. After receiving an application, the USPTO will review the patent application for completeness. In order for a patent application to be complete and move on to the prosecution process where the patent examiner will begin to substantively consider the application, the application must include: (1) a specification including at least one claim (see 37 C.F.R. §§ 1.71-1.77), (2) an inventor’s oath or declaration (see 37 C.F.R. §§ 1.63-1.64), (3) requisite fees (see 37 C.F.R. § 1.16), (4) and drawings, if necessary to convey the invention (see 37 C.F.R. §§ 1.81-1.85). Drawings are virtually always necessary, and should be deemed essential for every application.

If an application is missing the inventor’s oath or declaration, requisite fees, or is not filed in English, the USPTO will send the applicant a Notice to File Missing Parts. See Manual of Patent Examining Procedure (“MPEP”) § 506(I)(C). If an application is missing drawings described in the specification (see MPEP § 601.01(g)) or is missing some of the pages of the specification (see MPEP § 601.01(d)), the USPTO will issue a Notice of Omitted Items to the applicant. If you receive one of these Notices it is imperative that you respond and correct the deficiency noted by the USPTO. Failure to respond will result in the application going abandoned.

Once the patent application is deemed complete, the application will be forwarded to a patent examiner (“Examiner”) who will inspect and analyze the merits of the patent application.


The next step in the process is for the Examiner to review the application for a potential restriction. The most common type of restriction is when the applicant is claiming inventions that are either independent (i.e., completely unrelated) or distinct (i.e., related but capable of separate manufacture and separate use). Said another way, the Examiner will go through the application and look to see if the applicant is claiming more than one invention (i.e., are the inventions independent or distinct). If an applicant is claiming more than one invention, the Examiner will require the applicant to select which invention the applicant wishes to proceed through the prosecution process with. See MPEP § 802.02. The applicant can still choose to seek patent protection for the non-selected invention(s) in the original application (“Parent Application”) through a divisional application. See MPEP § 201.07.

In the event more than one invention is present and a restriction is issued by the Examiner, once the applicant has successfully narrowed his or her application down to a single invention to the satisfaction of the Examiner, the Examiner will move onto the substantive examination phase.

Substantive Examination

In the substantive examination phase, the Examiner will search through prior art in order to determine if the applicant’s claimed invention is different enough from what is already known to warrant patent protection. See MPEP §§ 904-904.03. The Examiner will search through whatever sources are available to him or her (e.g., previously granted patents, scholarly publications, industry publications, etc.) in order to ensure that the application’s claimed invention deserves patent protection. See MPEP § 904. Further, the Examiner will carefully go through the application to ensure that the application satisfies the requirements of 35 U.S.C. § 112, which is to say that the examiner will make sure that the invention is adequately described so that the invention can satisfactorily be understood by those of skill in the technology area or scientific field.

First Official Action on the Merits

After the Examiner has performed a prior art search and examined the application for § 112 defects, the Examiner will submit to the applicant the First Office Action. See MPEP § 2660. The First Office Action performs two functions. First, the First Office Action informs the applicant what parts of the application are allowable. Second, the First Office Action identifies all of the deficiencies of the application that the applicant will need to remedy in order for the patent to be granted. See 37 C.F.R. § 1.104. To remedy the defects in the patent application, an applicant submits a response to the Examiner.

It is important for those who are new to the field not to panic when they receive the First Office Action. This First Office Action can frequently make it seem like all hope is lost. Review the First Office Action, read the patents and references cited, and take some time to let it sink in and attempt to see things through the eyes of the Examiner. It can be useful to have a phone call with the Examiner, called an “interview”, in order to try and work things out and get closer to resolution.

Applicant’s Response

The USPTO will give an applicant two (3) months to respond to the First Office Action with an Amendment to remedy the defects of the application. See MPEP § 710.02(b). The USPTO will allow for possible automatic extensions of this deadline up to an additional three (3) months.  However, time period for a response cannot exceed a total of six (6) months. See 35 U.S.C. § 133.          

In the response to the First Office Action, the applicant must respond to each and every issue the Examiner raised in the First Office Action and provide reasoning to overcome the Examiner’s grounds for objection or rejection. See 37 C.F.R. § 1.111(b); see also MPEP § 2666. Addressing everything raised by the examiner can include arguing that the examiner is mistaken, amending claims to take into account examiner rejections and objections, or both.

The applicant may change and rearrange the application’s specification, claims, and drawings. See MPEP § 2163.07. However, the applicant is not permitted to add new material to the application that was not present in the application when the application was originally filed. See MPEP § 706.03(O). The applicant must remedy the application’s defects using only the matter that was in the application when it was originally filed.

After the applicant submits the Amendment to the Examiner, the Examiner will review the Amendment.


Examiner Review of Applicant’s Response

After receiving the applicant’s Amendment, the Examiner will review the application – looking for the same kinds of defects which led to the First Office Action. If the response to the First Office Action was merely to argue with the Examiner it should not be surprising that in nearly all cases (if not all cases) the Examiner will simply ratify their previous rejections. For that reason, it is generally important to make at least some amendments, or add some new claims that were supported by the originally filed disclosure so that the Examiner has something different to consider.

The Examiner’s review of the application this second time can go one of several ways. First, if the Examiner is satisfied that the Amendment dealt with each of the examiner’s previous objections or rejections detailed in the First Office Action then the examiner will allow the application to proceed by granting the applicant a Notice of Allowance (see below). See MPEP § 1.311. Second, if the Examiner is not satisfied that the Amendment resolved each and every objection and rejection set forth in the First Office Action, then the Examiner will issue a Second Official Action.

Second Official Action on the Merits

Like the First Office Action, the Second Office Action performs two functions. First, the Second Office Action informs the applicant what parts of the application are allowable. Second, the Second Office Action identifies all of the deficiencies of the application that the applicant will need to remedy in order for the patent to be granted.

For example, is possible that the combination of amendments and arguments made in response to the First Office Action resulted in some claims being deemed allowable while others continue to remain rejected. If that is the case the Examiner will specifically identify which claims are allowable and which remain rejected. The Examiner can, and sometimes will, also identify claims that could easily be made allowable by re-writing the form of the claim.

In rare circumstances, the Second Office Action can be a Non-Final Office Action. See MPEP § 706.07(a). A Non-Final Second Office Action is treated exactly like a First Office Action. Id. In most circumstances, the Second Office Action will be a Final Office Action. Id.

Final Office Action (“Final Rejection”)

A Final Office Action is also called a Final Rejection. Id. A Final Rejection carries restrictive implications for the applicant. See MPEP § 2271.   An examiner will issue a Final Rejection when the Examiner is able to makes same rejection for a second time (i.e., applicant’s Amendment did not remedy the defect and the same statutory basis for a rejection can be raised). See 37 C.F.R. § 1.113.

The name “Final Rejection” is a bit of a misnomer. Receiving a Final Rejection does not mean that a patent application has been completely rejected by the USPTO and cannot be saved. Instead, what it means is that this Second Office Action has started the final six (6) month clock on the patent application. See 35 U.S.C. § 133. Thus, time is winding down for the applicant on this filing once a Final Rejection is received.

Response after Final Rejection

After receiving a Final Rejection, an applicant can continue to amend the application and try to convince the Examiner to grant the application (allowed), an applicant can appeal the Examiner’s decision, or the applicant can abandon the application.

Following a Final Rejection an applicant is severely limited in how he or she is permitted to amend his or her application. An applicant may not add new claims or make substantive changes to existing claims. Id. Amendments made to an application after a Final Rejection are adopted if, and only if, they: (1) reduce the issues for appeal or (2) adopt the Examiner’s recommendations for resolving objections or rejections detailed in the Final Rejection. See MPEP § 2272.

Request for Continued Examination (“RCE”)

Submitting a Request for Continued Examination (RCE) is the typical way applicants who have no allowed claims get around the restrictions that a Final Rejection imposes upon an applicant. See 37 C.F.R. § 1.114. An RCE allows for continued prosecution of a patent application even after an Examiner has issued a Final Rejection. The USPTO will withdraw the “finality” of a Final Rejection and will “reset” the Examiner’s Office Action counter. Id. That is to say that after an RCE, an applicant will essentially get to start over at the First Office Action step. The applicant will get the benefit of another Non-Final Office Action as well as another Final Rejection. There is no limit to the number of RCEs an applicant can be granted. See MPEP § 706.07(h).

The only downside to filing an RCE is there is a filing fee cost, but you retain the earlier filing date of the original application. See 37 C.F.R. 1.17(e)(1). Another thing to know about an RCE is that if the Examiner can make the same rejection in an RCE as previously made in the Parent Application the First Office Action in the RCE can be made final. Thus, it is very important that something different be given to the Examiner to consider when filing an RCE.

Notice of Allowance

The applicant’s goal throughout the prosecution process is to convince the Examiner to grant a Notice of Allowance. See MPEP § 1303. When the Examiner believes that the applicant is entitled to patent protection for the claimed invention, the Examiner will issue a Notice of Allowance to the applicant. A Notice of Allowance can only be issued, however, if all the claims in the patent application are allowable. For that reason, at the end of a prosecution if there are allowable claims the choice is frequently made to cancel claims that remain rejected, which will then result in an application that has only allowed claims. At that point the Examiner would issue a Notice of Allowance. Those rejected claims can then be pursued in a continuation application, which if filed prior to the date the patent issues would be entitled to the priority filing date of the parent application.

In addition to notifying the applicant that his or her application is sufficient to be granted patent protection, the Notice of Allowance also indicates to the applicant what remaining fees are to be paid in order to issue the patent. The applicant has three months to pay the issue fee. This deadline to pay the issue fee cannot be extended for any reason.


If all attempts to convince the Examiner to issue the patent fail, the applicant may wish to consider filing a Notice of Appeal. See MPEP § 1204. The appeal will be heard by the Patent Trial and Appeals Board (PTAB) of the USPTO. Id. The PTAB will hear arguments and decide whether or not to grant the patent application over the objections of the Examiner. Prior to getting to Appeal, however, there are several opportunities remaining to convince the Examiner to still issue the patent. Indeed, the PTAB does not officially obtain jurisdiction over the appeal until rather late in the process.

For example, the applicant first files a Notice of Appeal and then has up to seven months (with extensions of time) to file an appeal brief. The Examiner must then file an Examiner’s Answer, which is a response to the appeal brief. After that, the applicant may file a Reply Brief, which responds to the Examiner’s Answer. Only after the time to file the Reply Brief has passed (or the Reply Brief has been filed) does jurisdiction over the appeal actually pass to the PTAB. For this reason, there can be strategic reasons in some situations to file an appeal even if you are not 100% convinced you want to go all the way through to appeal. The Examiner may pull the case back into prosecution when they see you are serious about an appeal, such as after you file an appeal brief. You may also be able to use a pre-appeal conference to convince the Examiner to issue claims. You can also always file an RCE while on appeal. The numerous possible options while on appeal and strategic reasons for pursuing those options goes beyond this primer.


If the Examiner will not grant a Notice of Allowance and the applicant is either unwilling to go through the appeals process, and does not wish to file an RCE. the applicant can abandon his or her application. See MPEP § 711. An applicant can formally abandon an application by notifying the USPTO that they would like to abandon the application or simply by failing to meet a deadline. Id. Alternatively, an applicant may choose to informally abandon an application in favor of a continuation application. See MPEP § 201.07. Abandonment in favor of a continuation application allows an applicant to re-open patent prosecution with the knowledge gained during the Parent Application prosecution. This may be a more time and cost-effective avenue than a RCE or an appeal, and would allow the applicant to add new matter into the application through the filing of a continuation-in-part application. Of course, the new matter would be given a new filing date commensurate with the filing date of the CIP, while the previously filed matter would be entitled to the filing date of the parent application, provided it is filed prior to abandonment of the parent.

Issue & Maintenance

After a Notice of Allowance is granted and all of the requisite issue fees are paid, the application is finally ready to be issued. See MPEP § 1309. The patent certificate is printed and shipped as soon as possible after the fees are paid, which is normally about 10 to 12 weeks thereafter Id. Even with the patent certificate in hand and prosecution process closed, the patent process is not quite over. After issuance, a patent holder is required to pay maintenance fees for the patent at three and a half (3 ½), seven and a half (7 ½) and (11 ½) years from the date the patent is granted. See MPEP § 2506. Failure to pay the maintenance fees can result in an early expiration of the exclusive rights conferred by a patent. See 17 C.F.R. § 1.362(g).


Obviously, there is a lot more to the patent prosecution process, but hopefully this overview provides a nice summary of the road ahead. For more information please see:


Warning & Disclaimer: The pages, articles and comments on IPWatchdog.com 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 IPWatchdog.com.

Join the Discussion

4 comments so far.

  • [Avatar for ceruleanverde]
    July 12, 2018 11:40 am

    TYPO: The USPTO will give an applicant two (3) months to respond

  • [Avatar for Poesito]
    July 3, 2018 05:03 pm

    Eric@2: The bill looks like a wish list for independent inventors and small entities to restore the U.S. patent regime. Seems unlikely that there will be any action on it in this Congress but I personally find it reassuring that there are rep’s in Congress who understand the issues well enough to put that bill on the table..

  • [Avatar for Eric Berend]
    Eric Berend
    July 2, 2018 10:14 pm

    @1., ‘Poesito’:

    Rep. Massie’s “Restoring America’s Leadership in Innovation Act of 2018” (H.R. 6264) is an excellent proposal for respecting and restoring the vast majority of historic U.S. patent law jurisprudence, as well as a sound Constitutional basis in statutory law.

    Given the exigencies of the current milieu, it seems a bit hopeful; however, it is so laudatory in its construction, that I believe it deserves an article by Gene here on IPWatchdog.com.

  • [Avatar for Poesito]
    July 2, 2018 01:35 am

    For an aspiring independent inventor and NPE hopeful like myself, these tutorials are interesting and valuable.

    Came across this https://rohrabacher.house.gov/press-release/updated-media-advisorypress-conference-reps-rohrabacher-kaptur-announce-bipartisan

    looking for info on this