The Number of U.S. Patents In Force

[10/25/14 updated to correct minor data collection error] 

by Dennis Crouch


The chart above shows the number of patents in-force at any given point over the past forty years.  Each bar represents a snapshot taken on January 1* of the stated year and totals-up the number of issued but not-yet-expired patents.  The data for each year is divided-up into four groups categorized according to age (years-from-issuance).  You’ll note the growth in young patents and a temporary decrease in older-patents.  The decrease is due to primarily to the establishment of maintenance fees for patents whose applications were filed after December 1980.

There have been a number of studies on the growth of patent enforcement litigation in recent years and some use the number of issued patents in order to calculate a litigation rate.  The problem with that approach is that that the number of patents potentially available for lawsuits in 2014 are not simply the number of patents issued that year, but rather include all patents in-force during the relevant time.

To make the chart, I first found the expected expiration date of each US utility patent going back to the 1950s, taking account of the 1995 changes in patent term calculation and the addition of patent-term-adjustment.  Then, I pulled-in data from the maintenance fee payment system and identified patents that expired early for failure to pay the maintenance fees due. Patent applications filed prior to December 1980 were not required to pay maintenance fees. I also identified patents that were associated with a terminal disclaimer and shortened the term where appropriate.  To do this, I actually guessed at which parent-patent was the likely relevant term — generally using the one with an earlier expiry date — because the actual link is buried in the prosecution history files.  I also did not have data on terminal disclaimers associated with pre-1976 patents. Using an automated process, I went through each of these steps with each patent in order to identify the years where it was in-force.  I should note, however, that I did not account regulatory-approval related patent term extensions or the impact of litigation/reexamination/review/reissue.  Although those processes are very important for particular patent rights, they are very unlikely to impact the general statistics presented here. Mike Brown (Brown & Michaels) has a good overview on his informative website.

* The final bar (2015) is a snapshot for October 23, 2014 (the day that the data was collected).

46 thoughts on “The Number of U.S. Patents In Force

  1. 11

    So, in 1998, there is an abrupt and dramatic change of gradient in the Dennis plot.

    1998 was also the year when the State Street Bank decision issued.

    Mere coincidence?

    Or cause and effect?

    1. 11.1

      You couple the timing information with the testimony to the Supreme Court that fully half of all patents pending or issued in recent years are of the computer implemented variety and it is clear that State Street Bank is proximate cause of the increase.

      And what the State Street Bank do? First, it found that price was tangible. Next, it implemented fully the concept that a programmed computer was per se statutory. Finally, it rejected, and ignored precedent of some vintage that business methods were not statutory subject matter, and that the patentable invention, if there was one, had to be in the statutory aspects of the claim.

      State Street Bank was a piece of work, the crowning achievement in the career of one judge who is held in high esteem by the patent bar, and by that esteem alone we know who one of the villains is in this tragedy. It is the patent bar.

      State Street Bank has to stand there is one of the most infamous decisions in the history of American jurisprudence. It will not be is well-known as Dred Scott, but we should all remember it for what it stands for. A decision that was both utterly shameless in its arrogance and its defiance of authority.

      1. 11.1.1

        …or just maybe we live in the age of innovation that is marked by the computer.

        May I suggest that you engage in some innovation reading – try Kondratieff and his K5 wave. See Trott, Innovation Management and New Product Development, pp 54-57.

  2. 10

    One interesting thing about all this patent talk is history. The Fed. Cir. started at the very end of the Carter administration. Since 1980 is really the modern era of patents. I would argue that the patent system is what has fueled the unbelievable innovation that has occurred since 1980. It has forced corporations (that have market power) to innovate or lose their position.

    That is reality. It is also reality that removing patents would be very much in the interest of Google.

    1. 10.1

      I really draw no such data from the graph. I just see that clearly the incentives seem to be making IP a more valued asset.

      1. 10.1.1

        What do you think happens when IP is more valuable? Companies hire researchers (Microsoft) and development teams to innovate to acquire the IP.

        What amazes is me is how ignorant most of the decision makers in IP policy making are.

        more valuable IP >> get more patents >>> spend more money on research >> put pressure on researchers to write patents

        GET: make examination a better process and you improve the last step for the whole country.

  3. 9

    Ned: It does seem that one should make themselves aware of what is patented in their field.

    I use a display in my field.

    Do I need to “be aware” of all the patents on displays wherein the display includes information similar to the information that appears on my own display?

    Or can I not bother doing that every week because the PTO would never issue such a patent?

    Other people who use displays in their field might be interested in the answer.

    How about people who use the public domain technique of PCR as a data-gathering tool for basic research? Do they need to check the patent database every Tuesday morning to be sure that it’s safe to continue using PCR “in their field”?

    1. 9.1

      Obviously MM, if you listen to the likes of Judge Rich who declared in State Street Bank that price was tangible, if you use a display to view the improved price of someone’s infringing service, like eBay, you are in infringer.

      Quake in your boots.

  4. 8

    I’m sure we are all wondering this but not indulging in any speculation, so let me encourage it a little:

    Anyone care to hazard a guess as to what happened on or about 1999, the effects of which have not stopped since?

    1. 8.1

      Anyone care to hazard a guess as to what happened on or about 1999, the effects of which have not stopped since?

      State Street was decided in July of 1998.

      1. 8.1.1

        I’d think the weakening of State Street by Bilski in 2010 (followed by Mayo and Alice) would have smoothed that graph out a little bit towards the right end.

        However, it takes on an even sharper upward trend at 2010.

        Maybe it’s just “inertia”. (Stored “energy” from the bubble still working it’s way through the PTO?)

    2. 8.2

      Yeah I don’t get it man, where are all these extra patents in force coming from other than State Street etc? Surely we’d be tamping down the growth a little with bilski etc. if that was the only thing. Almost has to be something else.

      Anyway, this graph shows exactly why people be hating on modern software patents. Way more than normal in force for one thing.

  5. 7

    It was dismaying to learn during the Teva v. Sandoz oral arguments that neither the Justices nor the attorneys seemed to have any clue about the number of patents that are granted each year, or the number of patents in force, much less the unprecedented and rapid swelling in those numbers that began 15-20 years ago with barely a hiccup since.

    1. 7.1

      Why is that dismaying? Would any of that information have any relevance to the issues in the case?

      1. 7.1.1

        Why is that dismaying?

        It just seems to me like a fundamental fact that any interested observer of the patent system should know, much less a lawyer who’s appearing before the Supreme Court to discuss a subject (claim construction) relevant to every one of those 2.5 million (and counting) patents.

        Would any of that information have any relevance to the issues in the case?

        As I recall, the question of the numbers was raised by Breyer during a discussion with the attorney for Sandoz about the importance of stare decisis and uniformity in the original Markman decision, given that every granted patent is binding on the public.

    2. 7.2

      I would like to see a graph comparing the number of patents issuing per year with the number of technical articles published per year.

      1. 7.2.1

        Your Computer Can Process Information

        by MM

        You can take a computer and configure it to determine the day of the week when you are likely to run out of organic cornflakes. Then the computer can automatically alert you to purchase more organic cornflakes, or it can create or update a shopping list to include said organic cornflakes. The cornflakes are sold in a box and the same computer can be configured to offer one or more games of chance, including seven-dimensional bingo. The computer can be big or small.

        The End

        There’s another “technical article” for you.

        So much innovation, so little time.


          We have all noticed how clever you are at writing about what was.

  6. 6

    I did a brief study several years ago in connection with a draft of the AIA legislation limiting PGRs to only the first 9 months of life of a patent after issuance. It showed that far more older patents were being sued on than such new patents, opposite from the percentages of patents in force and available for suit at that age. [Including the fact that even expired patents can be sued on for up to six years, for declining years of partial back infringement damages.] In other words, that PGR would be of limited use because so relatively few companies are sued on such very new patents.
    Since the above and other data shows a significant increase in new patents as a percentage of all patents in force, it would be interesting to see a more currrent comparison of what percentage of patents less than 9 months old are being actually asserted these days?

    1. 6.1

      Good points, Curmudgeon – but one pro and one con comment:

      pro: certain expired patents (not lapsed for non-payment) should be included
      con: PGR can be considered to be specifically aimed for the growing number of new patents and is a new addition to the t001s available – not created for a direct comparison as your comment indicates.

      I would consider your comment though still valid for asking whether such a t001 was warranted, or whether such is more likely merely a reflection of “hysteria driving legislation” – and might serve as a proxy indicator of legislative process capture.

      I agree with you that the data at the very least would be interesting.

  7. 5

    And remember, folks, it’s strict liability. You’re on notice of the contents of every one of those 2.5M patents!

    1. 5.1


      I disagree with the notion that you are on notice – mere publication is not the same as notice.

      However, I would posit that the Office would be better off if a presumption of notice were in effect for mere publication – at least in respect to some type of art field – business category correlation (for example, NAIC codes).

      One aspect of the word “promote” that is often not as recognized as much as it should be is the aspect of promotion – as in providing notice through a promotional flyer. If businesses were charted with at least keeping up with new patent publications in their respective NAIC-related coded art fields through the mechanism of presumed knowledge, the mission of the Patent Office would itself be promoted.

      I think this would be a fair balance to the legal notion of Person Having Ordinary Skill In The Art to which the invention pertains that those obtaining patents must pass.

      1. 5.1.1

        Sorry, I’m afraid that I don’t see how your suggestion provides a “fair balance” to the notion of the PHOSITA.

        But to your proposal, what would the effect of this presumption of notice be? Are you suggesting that every infringement should be deemed willful, so long as the infringed patent relates to the infringer’s business? Or do you have other consequences in mind for those businesses that fail to read all of the patents in their business area?

    2. 5.2

      DanH, notice is not the right word.

      “Ignorance of the law” is no excuse comes to mind. It does seem that one should make themselves aware of what is patented in their field.

      That is why claims have to be clear.

      1. 5.2.1

        DanH, notice is not the right word.

        Agreed, Ned. All I meant was that all of us potential infringers should get started on reading those patents. We’ve got a lot of reading to do!

        It does seem that one should make themselves aware of what is patented in their field.

        Hmm. I run a small business, Ned. What field(s) do you think I should limit my review of those 2.5M patents to?

  8. 4

    Dennis, can you normalize the data? Meaning, show what percentage of all patents in force in a particular year fall in the different age categories?

      1. 4.1.2

        Flipping the graph upside down (building the completed stacks from the perspective of oldest “innovation-proxy” first, one could make the argument that the trending lower of all non-blue items is a positive sign that there is more (recent) innovation activity – a healthy indicator that we are not resting on our laurals.

        Conversely, those times of rising resting-on-our-laurals do correlate with our country experiencing economic stagnation and our country being in pain.

        While it will be correctly noted that correlation is not the same as cause, such a statement should not be used to ignore the fact of the correlation.

  9. 2

    I recall one of the amicus briefs in the reason Alice case that said the fully half of all the pending applications in the patent office were of the “computer implemented” variety. It seems quite apparent that State Street Bank, or was that Alappat, opened the floodgate.

    1. 2.1

      “open the flood gates” ????

      To what? Innovation?

      Try to remember that information processing now accounts for a large portion of economy. That it is probably the biggest driver of our economy.

      1. 2.1.1


        I don’t think anyone here believes that information processing is not both vitally important to our economy and the source of much innovation.

        Instead, many of us believe that information processing patents present some unique issues and have led to a number of problems with our patent system.

        I think keeping those two issues separate is important.



          I think I see the point that you are trying to make.

          However, the counter point would be that any such concern about unique issues cannot be an open invitation to muddle the understanding of what the law means, nor a valid reason to seek judicial activism to change the law for policy reasons, as policy driven law changes are the dominion of the Congress.

          Many of us here that feel strongly about such matters would love a discussion on the merits of any such issues that you see – but would demand that those discussions reflect an intellectually honest (if you would permit my use of that term) appreciation of how the statutory law – that patent law falls expressly into under our constitution – is set up to be written.

          I will further note (again) that this is not to say that Congress cannot decide to share its authority in areas that it has decided to do so. I have provided as an example of such sharing the explicit words of Congress as found in 35 USC 283: “The several courts having jurisdiction of cases under this title may grant injunctions in accordance with the principles of equity to prevent the violation of any right secured by patent, on such terms as the court deems reasonable.

          But such an invitation is not only NOT found in 35 USC 101, the creation of that section of law in 1952 is intimately tied into the creation of 35 USC 103, and the explicit decision by Congress to remove a previously granted power of developing the definition of “invention” by common law mechanism.


          The problem is that those “unique issues” are fabricated and do not reflect reality. I think separating fabricated problems from real problems is important and fairly characterizing information processing.

          Please try to remember that.


            The relationship between the weather and the average time that my mail is delivered on Wednesdays.

            An expired copyright on a movie featuring twenty singing goats riding on broken lawnmowers.

            (Y/50.3432) x (42/Z + 2.)

            A pencil coated in rubber, wherein said rubber is dimpled, wherein said dimples are between 0.1 and 0.2 cm in diameter and wherein the number of dimples is between 500 and 1000.

            Pretty sure that one of those things is not like the others, at least as far as patent law is concerned. And that’s not “a fabrication.”


              I am pretty sure that you regularly deny reality. You run over the structure question and claim that I “feel” there is structure despite Mano, despite Susskind, etc.

              Moreover, what you just typed has no meaning without context.


              Moreover you have never explained how it is that you have 10 hours a day to blog.

  10. 1

    Great chart! I do find myself gripped by an irrational desire to know the “exact” current number, in all of its significant and insignificant digits. Looks like it’s just a hair shy of 2.5 million?

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