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Patent Interference and Derivation Proceedings

April 26, 2026 Aruna 10 min read
Patent Interference and Derivation Proceedings — intellectual property law and protection

When two inventors claim the same invention, the patent system must determine who has the right to the patent. Historically, this was resolved through interference proceedings under the first-to-invent system. With the passage of the America Invents Act (AIA) in 2011, the U.S. transitioned to a first-inventor-to-file system, replacing interference proceedings with derivation proceedings for applications subject to the AIA. Understanding both types of proceedings — and when each applies — is essential for inventors and patent practitioners alike. At PerspireIP, we guide clients through these complex disputes. This guide explains how patent interference and derivation proceedings work and what you need to know to protect your rights.

Patent Interference Proceedings: The Pre-AIA System

Before March 16, 2013 (the effective date of the AIA’s first-inventor-to-file provisions), the United States operated under a first-to-invent system. Under this system, when two patent applications claimed the same invention, a proceeding called an interference was conducted to determine which inventor had the right to a patent. Interference proceedings were conducted before the Board of Patent Appeals and Interferences (now the PTAB) and could result in extensive fact-finding about the dates of conception, reduction to practice, and diligence of each party’s inventors.

Although the AIA eliminated interference proceedings for most applications, they remain relevant today for applications and patents subject to pre-AIA law — specifically, applications with at least one claim that has an effective filing date before March 16, 2013. The USPTO can still declare an interference between such applications, and existing patents and applications from this era may still face interference challenges.

Patent Derivation Proceedings: The AIA System

Under the AIA’s first-inventor-to-file system, the patent goes to the first inventor to file — not necessarily the first to invent. This makes filing date paramount and eliminates most disputes about who invented first. However, one scenario the AIA addressed is derivation: when a later-filed patent application was derived from the true inventor’s work without authorization. A patent derivation proceeding is a mechanism for the true inventor to challenge a patent or application that was improperly derived from their invention.

A derivation proceeding is instituted by the PTAB when a petitioner (typically the true inventor or their assignee) demonstrates that the claimed invention in the earlier-filed application was derived from the petitioner’s inventive work and that the petitioner filed their application within 1 year of the publication of the earlier application. The proceeding determines whether the named inventor in the earlier application actually derived the invention from the petitioner.

Key Differences Between Interference and Derivation Proceedings

Understanding the distinction between interference and patent derivation proceedings is important for assessing your options in a priority dispute.

  • Interference applies to pre-AIA applications and determines which of two parties was the first to invent a claimed invention.
  • Derivation applies to AIA applications and determines whether an earlier filer derived the claimed invention from a later filer (the true inventor).
  • In interference, either party can prevail by proving they invented first; in derivation, only the true inventor (the party claiming derivation) can prevail by proving the other party copied their work.
  • Derivation proceedings require proof of prior conception by the petitioner and communication of that conception to the respondent before the respondent’s filing date.

When to Consider a Derivation Proceeding

A patent derivation proceeding may be appropriate when you have evidence that a competitor’s patent application claims an invention that originated with you. Common scenarios include situations where a former employee, contractor, or collaborator files a patent application on an invention they learned from you in the course of a confidential relationship. Another scenario is when a company patents technology that was shared in confidence during merger discussions, licensing negotiations, or vendor relationships. Derivation proceedings are powerful but require strong evidence — you must be able to demonstrate both that you conceived the invention before the respondent and that you communicated that conception to the respondent.

Protecting Against Derivation Claims

To protect against derivation claims against your own patents, it is essential to maintain rigorous invention disclosure and documentation practices. Keep dated records of all invention disclosures, research notes, prototypes, and communications. Use formal invention disclosure forms that are signed and dated by all inventors. When sharing confidential information with others, use confidentiality agreements that clearly establish the source of the disclosed technology. These practices are not only good IP hygiene — they are critical evidence if you ever face a derivation challenge.

The PTAB Derivation Proceeding Process

A derivation proceeding before the PTAB is a complex, adversarial proceeding with specific procedural requirements. The petitioner must file a petition within 1 year of the publication of the earlier application, setting out the evidence of derivation with supporting declarations and exhibits. The PTAB evaluates whether the petition demonstrates that derivation is reasonably likely. If instituted, the proceeding involves document discovery, depositions, expert testimony, and trial briefs before the PTAB issues a final written decision. Parties may appeal PTAB decisions to the Federal Circuit.

What 35 U.S.C. 135 Actually Requires

The statutory basis for derivation proceedings is 35 U.S.C. 135, as rewritten by the America Invents Act. Read closely, it sets a narrow test, and most petitions that fail do so because they argue the wrong thing.

The petition has to demonstrate two elements together. First, that an inventor named in the earlier application derived the claimed invention from an individual named as an inventor or joint inventor in the petitioner’s own application. Second, that the earlier application claiming that invention was filed without authorization. Derivation is therefore about communication plus unauthorised filing — not about who got to the invention first.

That distinction is the heart of the post-AIA system. Under the first-inventor-to-file regime, being earlier is no longer a ground for relief on its own. A derivation petition does not ask the Board to decide who invented first; it asks the Board to find that the other side got the invention from your inventor and filed on it anyway.

  • Communication of the invention from the petitioner’s named inventor to the respondent’s named inventor
  • A filing by the respondent claiming that invention
  • Absence of authorisation for that filing
  • A petition supported by substantial evidence, filed within the statutory window

The regulations require the parties to provide sufficient evidence to prove and rebut a claim of derivation, so corroboration matters enormously. Uncorroborated inventor testimony is the most common reason a derivation claim collapses.

The One-Year Window, and Why It Closes Earlier Than People Expect

The deadline in 35 U.S.C. 135 is unforgiving and it is frequently miscalculated. A petition must be filed during the one-year period following the date on which the patent containing the disputed claim was granted, or the date on which the earlier application containing that claim was published — whichever is earlier.

The “whichever is earlier” clause is the trap. Teams often diarise one year from grant, but publication of the earlier application almost always precedes grant, and it is publication that starts the clock in that case. By the time a patent issues and someone notices the problem, the window may have closed a year or more previously.

The practical consequence is that derivation has to be a monitoring discipline rather than a litigation reaction. If you have disclosed an invention to a collaborator, supplier or departing employee, the publication of their application is the event you need to catch — not the grant of their patent.

Where the window has closed, 35 U.S.C. 291 provides a separate civil action in the district courts in respect of derived patents, on its own terms and timing. It is not a substitute for a timely petition, but it is worth checking before concluding that nothing can be done.

Who Decides, and How a Proceeding Ends

Institution and decision are split. The Director decides whether to institute a derivation proceeding, and that institution decision is final and not appealable. Once instituted, the Patent Trial and Appeal Board conducts the proceeding and makes the determination on derivation and correct inventorship.

Two exit routes are built into the statute and both are used more often than a full trial. The parties may terminate the proceeding by filing a written agreement identifying the correct inventor, and the Board will accept that agreement unless it is inconsistent with the evidence before it. Alternatively, the parties may submit the dispute to arbitration under federal arbitration law; the award binds the parties once the Director has been notified, though the Director retains authority over patentability.

That last point is the one commercial parties most often miss. Settling or arbitrating inventorship resolves the dispute between the parties. It does not oblige the Office to grant a patent, because patentability remains the Director’s question.

Derivation Proceedings Compared With the Alternatives

Derivation is narrow, and choosing it when something else fits the facts wastes the one-year window. The question to ask is what is actually wrong with the other side’s patent or application.

  • They got the invention from us and filed without permission. That is derivation, and 35 U.S.C. 135 is the route.
  • Their claims are unpatentable over prior art. That is an inter partes review or a post-grant review, not a derivation proceeding. Derivation does not turn on prior art at all.
  • The named inventors are simply wrong, with no wrongdoing. That is an inventorship correction, which is an administrative fix rather than a contested proceeding.
  • The dispute is really about a contract or an NDA. That belongs in court on the agreement, and it will often be faster and broader in remedy than a Board proceeding.

It is also worth being clear about what derivation proceedings replaced. Patent interference proceedings decided priority of invention under the pre-AIA first-to-invent system. They have not been abolished retroactively — applications and patents with effective filing dates before 16 March 2013 can still raise interference questions — but for anything filed after that date, derivation is the live mechanism and priority of invention is no longer the issue.

Building an Evidentiary Record Before You Need It

Derivation cases are won on contemporaneous records, and the records that matter are created long before anyone contemplates a petition. The teams that succeed are the ones that can show, with dated documents, exactly what was communicated to whom.

  • Date and witness invention disclosures internally, and keep the version history rather than only the final document
  • Log every external disclosure — the date, the recipient, the subject matter, and the agreement it was made under
  • Keep the transmission evidence, not just the content: the email, the portal log, the courier receipt
  • Run an NDA before technical discussions, and make the scope of permitted use explicit rather than implied
  • Monitor publications and filings by collaborators, suppliers and former employees, so the one-year clock is caught at publication
  • Preserve the departing-employee record — exit interviews, device returns, and acknowledgement of continuing obligations

None of this is specific to derivation, which is rather the point. The same record that supports a derivation petition also supports a trade secret claim, a contract claim and an inventorship correction, so the cost of keeping it is spread across every route you might eventually need.

How PerspireIP Can Help

Whether you are asserting a derivation claim against an applicant who has appropriated your invention, or defending your application against a derivation petition, PerspireIP provides experienced counsel in patent derivation proceedings and interference matters. Our attorneys understand both the substantive law and the complex procedural rules governing these proceedings, and we develop aggressive, evidence-based strategies to protect our clients’ inventorship rights.

Conclusion

Patent interference and derivation proceedings address some of the most complex and consequential disputes in patent law — disputes over who truly invented the claimed technology. Understanding when these proceedings apply and how they work is essential for protecting your IP rights. If you believe a competitor has filed a patent on your invention, or if you are facing a challenge to your inventorship, PerspireIP is here to help. Contact us today for an assessment of your situation.