Can you file a continuation to cover a competitor’s product?

Yes. The Federal Circuit said so directly in Kingsdown Medical Consultants, Ltd. v. Hollister Inc., 863 F.2d 867 (Fed. Cir. 1988):

“[T]here is nothing improper, illegal or inequitable in filing a patent application for the purpose of obtaining a right to exclude a known competitor’s product from the market; nor is it in any manner improper to amend or insert claims intended to cover a competitor’s product the applicant’s attorney has learned about during the prosecution of a patent application.”

The court added that if the claims comply with the statute and rules, their marketplace origin “cannot of itself evidence deceitful intent,” and it reversed the inequitable-conduct ruling. One precision for briefs: this passage is in the panel portion of the opinion. Only the section on intent and gross negligence was decided in banc.

The condition is stated in Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 909 (Fed. Cir. 2004), as quoted in Sonos: it is not improper to broaden claims to encompass a competitor’s products “as long as the disclosure supports the broadened claims.” The rest of this page is about meeting that condition, and about the timing risks around it.

A continuation takes the parent’s specification as filed and lets you present new claims with the parent’s filing date. Three conditions make it available:

• A pending parent. The continuation must be filed “before the patenting or abandonment of or termination of proceedings on” the parent (35 U.S.C. 120). Filing on the issue date is timely (MPEP 211.01(b)).
• A nonprovisional parent. A provisional can never be the parent of a continuation. The family needs a pending nonprovisional, or a pending PCT or Hague application designating the US.
• An unbroken chain. Each intermediate application must have been copending with its own parent. A gap anywhere breaks benefit for everything below it.

That is why some applicants keep a member of each important family pending. Each new continuation, filed before its parent issues, keeps the specification available for claims you cannot yet foresee. The timing rules are set out in the continuation deadline explainer.

Written-description support in the specification as filed. Nothing learned from the competitor’s product can be added. Two decisions frame the risk.

Quake v. Lo, 928 F.3d 1365 (Fed. Cir. 2019), affirmed that claims added after a rival’s application published lacked written description. The court stressed the point:

“‘[T]he purpose of the written description requirement is to prevent an applicant from later asserting that he invented that which he did not,’ and the requirement is particularly important when, as here, claims are added later during prosecution in response to development by others.” (slip op. at 15)

Mondis Technology v. LG Electronics (Fed. Cir. Aug. 8, 2025, precedential) reversed a jury verdict and held two claims invalid for lack of written description. The limitation had been added to overcome prior art, not to cover a competitor. But the holding applies to any added limitation: the examiner’s allowance “by itself” is not substantial evidence of § 112 compliance. “If it did, there would rarely be a situation where an issued patent could later be invalidated for lack of written description.”

In practice, every element of the new claim needs a paragraph you can cite, quote and defend in litigation. Express support beats inference. Where a feature of the product appears nowhere in the specification, leave it out of the claim.

Yes, in extreme cases. Laches may render a patent unenforceable when it issued “only after an unreasonable and unexplained delay in prosecution that constitutes an egregious misuse of the statutory patent system under a totality of the circumstances” (Hyatt v. Hirshfeld, Fed. Cir. 2021, quoting Cancer Research Technology). Recent decisions point in different directions.

Google LLC v. Sonos, Inc., No. 2024-1097 (Fed. Cir. Aug. 28, 2025) (nonprecedential). The claims rested on a 2007 specification. The court reversed the rulings that had held two patents invalid for lack of written description and unenforceable for laches. Those rulings had wiped out Sonos’s $32.5 million jury verdict, and the case went back for the remaining post-trial motions. On laches, the court found no prejudice, because the specification had published in 2013, before Google’s asserted investment:

“Google cannot be prejudiced by incorporating into its products a feature that was publicly disclosed in a patent application prior to its investment.” (slip op. at 16)

The court did not decide whether the roughly 13-year delay was unreasonable. As a nonprecedential decision resting on prejudice alone, Sonos illustrates a defense; it does not establish a safe harbor.

Hyatt v. Stewart, 148 F.4th 1376 (Fed. Cir. 2025). The court affirmed the USPTO’s laches defense against Hyatt’s applications. The Supreme Court denied cert on June 29, 2026 and rehearing on Sept. 4, 2026 (No. 25-1049). In Personalized Media v. Apple (Fed. Cir. 2023), an issued patent was held unenforceable; the defendant can show prejudice by proving it “invested in, worked on, or used the claimed technology during the period of delay.”

US 10,433,776 (“Low power pulse oximeter”) is a public example. Its application, 16/174,144, was filed on Oct. 29, 2018 as a continuation in a chain back to 10/184,028 (filed June 26, 2002), with earliest priority to a provisional filed July 2, 2001. It issued on Oct. 8, 2019, about 11 months after filing.

On Nov. 14, 2025, a jury in Masimo Corp. v. Apple Inc., No. 8:20-cv-00048 (C.D. Cal.), returned a verdict of $634,313,913 for Masimo on claims 11–14. Final judgment was entered on July 20, 2026, keeping the verdict (Bloomberg Law). Prejudgment interest awarded on Oct. 5, 2026 brings the reported total to about $818 million (report). Masimo filed a notice of appeal, and Apple has said it will appeal. Status as of Oct. 23, 2026; both post-trial figures come from press reports.

The point for practitioners: claims filed 17 years after the earliest priority date issued in 11 months and held up through final judgment. Filed today, the same continuation would also owe the 9-year continuation surcharge (our calculation: its earliest benefit date is June 26, 2002).

USPTO fees for a large entity, filed in Patent Center in DOCX, with up to 20 claims and 3 independent claims (fee schedule). Small and micro entities pay less.

Worked total: $4,700 at filing in years 6 to 9; $9,365 with Track One; $10,665 with Track One after year 9.

The surcharge clock. The continuing application fee (37 CFR 1.17(w)) is counted from the earliest benefit date under §§ 120, 121, 365(c) or 386(c). Provisional and foreign priority dates do not count. The tiers do not stack: the 9-year amount is the total. If it is not paid, the benefit claim is not entered. Details and a calculator: how the continuation surcharge is counted.

Track One timing. On the USPTO dashboard for FY2026, prioritized examination took 4.93 months from petition grant to final disposition, and about 7 months from filing (dashboard). The request must be made on filing, with at most 4 independent and 30 total claims and no multiple dependent claims (37 CFR 1.102(e)). The annual cap is 20,000 requests since July 8, 2025 (90 FR 29990). The USPTO publishes no Track One allowance rate.

1. Watch for launches. Track competitor product pages, manuals and release notes. Record the URL and the date accessed for every feature you rely on.
2. Check which families are still pending. List every pending nonprovisional in each candidate family, with its status: under examination, allowed, issue fee paid. Once the issue fee is paid, issue follows within weeks.
3. Map product features to as-filed paragraphs. For each feature, find the paragraph and figure that describe it in the specification as filed. Grade the support: express, implied, or inference only.
4. Draft claims for support first. Build each element from supported language. Drop or redraft any element whose only support is an inference. Coverage of the product comes second.
5. Decide on Track One. Weigh $4,665 against months of pendency, and check the claim limits before filing.
6. File on or before the parent’s issue date. Ideally before the issue fee is paid. The filing date is the Patent Center receipt date in Eastern Time.

This is the sequence we follow in a review. See how it works.

One row per claim element: the element, the as-filed paragraph that supports it, and the public documentation for the product feature it may correspond to. Weak rows stay visible. In this example the wireless element is dropped, because the specification mentions only “a communication module.”

At every step. A support map is evidence for a decision, not the decision. Whether to file, which claims to present, and whether a given element has adequate written description are for your registered patent practitioner.

• Claims must be supported. Kingsdown protects the motive, not unsupported claims.
• Talk about support, not liability. A pending application has no enforceable claims. The right statement is that the specification may support claims covering a feature described in public documentation.
• Use public information only. Product facts come from published documentation, cited with the date accessed.