Claiming the Destination: When a Desired Effect Receives Patentable Weight

Executive Summary: Patent claims frequently state not only what an invention is or does, but what it is intended to accomplish: reducing latency, improving stability, treating disease, preventing movement, or achieving a specified performance level. Whether that language receives “patentable weight” cannot be answered by a rule about words such as “whereby,” “wherein,” “for,” or “configured to.” The sound analysis has three gates, the second of which is conditional. Gate One is claim construction: what does the language require—purpose, capability, configuration, conduct, actual achievement, or an objective threshold? Gate Two is the conditional functional-relationship inquiry: when the asserted distinction lies in communicative, instructional, validation, epistemic, or reputational content, does that content interact with the remaining claim elements to create claimed functionality or cause a claimed action? Gate Three is prior-art satisfaction: is the patentability-relevant requirement expressly disclosed, necessarily present, or the result of an obvious modification or optimization supported by the requisite motivation and reasonable expectation of success and, for optimization, a recognized result-effective variable? An ordinary structural, configurational, operational, or actual-performance requirement generally proceeds from construction to Gate Three without a separate printed-matter screen.

I.                   Introduction

Patent claims often describe not only what the inventor makes or does, but what the invention is supposed to accomplish. A method claim may end with “whereby latency is reduced.” An apparatus claim may recite a controller “configured to reduce power consumption.” A treatment claim may require administration of a drug “wherein the method reduces the incidence of an adverse event.” Each formulation points toward a desired effect. Yet the legal consequences can differ sharply.

Courts and the U.S. Patent and Trademark Office often ask whether such language is entitled to “patentable weight.” That shorthand can obscure three distinct questions. The first is one of claim construction: does the desired-effect language impose a requirement on the claim, and if so, what does it require? The second is the conditional functional-relationship inquiry: when the asserted distinction lies in communicative content, instructions, knowledge, proof, approval, certification, validation, or reputation, does that content interact functionally with the remaining claim elements? The third compares any patentability-relevant requirement with the prior art through the distinct doctrines of express disclosure, inherency, obvious modification or combination, and routine optimization.

Those legal propositions must be stated separately even when a tribunal resolves them together procedurally. A desired effect may be a genuine claim limitation yet fail to distinguish the prior art because the same effect necessarily occurred in a prior-art process. A phrase also may limit scope in some sense while describing only later proof, approval, certification, or acclaim that does not alter the claimed structure or conduct. Conversely, language that does not limit claim scope may still describe an important commercial benefit, although it cannot supply a patentable distinction. The analytical error is to treat “patentable weight” as a single yes-or-no conclusion.

The Federal Circuit’s decision in Bayer Pharma Aktiengesellschaft v. Mylan Pharmaceuticals Inc. makes the conditional intermediate inquiry unavoidable when the asserted distinction lies in validation or epistemic content. The court declined to decide whether “clinically proven effective” was limiting and declined to decide whether it was inherently anticipated. It held instead that, even if limiting, the phrase was functionally unrelated to the recited treatment method and therefore could not make the otherwise unpatentable method patentable. 152 F.4th 1400, 1404–06 (Fed. Cir. 2025).

The better framework therefore has three gates. At Gate One, the decisionmaker construes the claim under the standard applicable to the forum. Gate Two—the conditional functional-relationship inquiry—applies when the asserted distinction is communicative, instructional, validation, epistemic, or reputational content; the decisionmaker then asks whether that content interacts with the remaining claim elements to create functionality or cause claimed conduct. If the disputed language instead imposes an ordinary structural, configurational, operational, or actual-performance requirement, the analysis ordinarily moves directly from construction to Gate Three. At Gate Three, the decisionmaker tests the patentability-relevant requirement against the prior art. Only after the applicable inquiries may one conclude that a desired effect contributes to patentability.

II.                What “Patentable Weight” Actually Means

The starting point is the claim as a whole. Patentability under 35 U.S.C. §§ 102 and 103 must be assessed against every limitation of the properly construed claim. “All words in a claim must be considered,” but that command does not answer whether every phrase appearing in the claim narrows its scope. In re Wilson, 424 F.2d 1382, 1385 (C.C.P.A. 1970); see U.S. Patent & Trademark Office, Manual of Patent Examining Procedure § 2143.03 (9th ed. Rev. 01.2024, Nov. 2024) [hereinafter MPEP]. Some language identifies the environment, intended use, or hoped-for benefit of an otherwise complete invention. Claim construction determines whether that language defines the metes and bounds. The MPEP remains important evidence of USPTO examination policy, but Revision 01.2024, published in November 2024, is substantively current only through January 31, 2024. The Office separately identifies post-cutoff rules, notices, guidance, and memoranda that have not been incorporated. A current-practice analysis must therefore consult those later authorities independently. See U.S. Patent & Trademark Off., Manual of Patent Examining Procedure (9th ed. Rev. 01.2024, Nov. 2024), https://www.uspto.gov/web/offices/pac/mpep/; U.S. Patent & Trademark Off., Subsequent Publications (After January 31, 2024) 1 (July 2026), https://www.uspto.gov/web/offices/pac/mpep/subsequent-publications.pdf.

The applicable construction standard depends on the forum. Federal courts, the International Trade Commission, and AIA trial proceedings generally apply the framework associated with Phillips v. AWH Corp., reading issued claims according to their ordinary and customary meaning to a skilled artisan in the context of the intrinsic record. 415 F.3d 1303, 1312–17 (Fed. Cir. 2005) (en banc); see Bio-Rad Laboratories, Inc. v. International Trade Commission, 998 F.3d 1320, 1344 (Fed. Cir. 2021); 37 C.F.R. §§ 42.100(b), 42.200(b). Pending claims in ordinary ex parte examination and ex parte appeal receive their broadest reasonable interpretation consistent with the specification—not the broadest possible interpretation. In re Morris, 127 F.3d 1048, 1054 (Fed. Cir. 1997); In re Suitco Surface, Inc., 603 F.3d 1255, 1259–60 (Fed. Cir. 2010); MPEP § 2111. The standards overlap substantially, but the procedural posture and the applicant’s opportunity to amend can affect the breadth assigned to desired-effect language.

Table 1. Claim-construction standards by forum

Forum or proceeding	Construction standard	Practical consequence
Federal courts and the ITC	The Phillips framework: ordinary and customary meaning to a skilled artisan in light of the intrinsic record	Issued claims are construed in an adjudicatory setting, without the ordinary examination opportunity to amend
IPR and PGR	The civil-action construction standard under 37 C.F.R. §§ 42.100(b) and 42.200(b)	A Phillips-type standard applies; amendment is available only through the proceeding’s limited procedures
Ordinary ex parte examination and appeal	Broadest reasonable interpretation consistent with the specification	Pending claims may receive a broader construction, and the applicant ordinarily has an opportunity to amend

The standards draw on much of the same intrinsic evidence, but the forum and the availability of amendment can affect the breadth assigned to desired-effect language.

Within the governing standard, there is no independent grammatical doctrine under which “whereby,” “wherein,” “for,” “so that,” “adapted to,” or “configured to” automatically receives—or automatically loses—limiting effect. The phrase’s role in the claim matters more than its introductory word. MPEP § 2111.04.

A useful vocabulary is therefore more precise than “weight.” In the construction inquiry, ask: What does the phrase require? Depending on context, it may require an actual result, a capability, a configuration designed for a function, a structural relationship, or merely an intended use. In the conditional functional-relationship inquiry, ask first: Is the asserted distinction information or status claimed for its communicative, instructional, evidentiary, regulatory, or reputational content? If so, ask whether that content interacts with the other claim elements to create claimed functionality or cause a claimed action. C R Bard Inc. v. AngioDynamics, Inc., 979 F.3d 1372, 1381–82 (Fed. Cir. 2020). When the phrase instead imposes an ordinary structural, configurational, operational, or actual-performance requirement, the analysis ordinarily proceeds without a separate printed-matter screen. In the prior-art inquiry, ask: How does the art satisfy the patentability-relevant requirement? Express disclosure, necessity, an obvious modification supported by motivation and reasonable expectation of success, and routine optimization of a recognized result-effective variable are separate routes with separate showings.

The printed-matter precedents describe their test as requiring a “new and unobvious functional relationship.” King Pharmaceuticals, Inc. v. Eon Labs, Inc., 616 F.3d 1267, 1279 (Fed. Cir. 2010) (quoting In re Ngai, 367 F.3d 1336, 1338 (Fed. Cir. 2004)). To preserve the framework’s sequencing, Gate Two asks whether the informational or status content is functionally integrated with the remaining elements at all. Gate Three then asks whether the claim—including any functionally integrated informational content or relationship—is new and nonobvious over the prior art.

This separation prevents a common non sequitur. A court’s conclusion that a desired result is limiting does not establish novelty. Likewise, a finding that prior art inherently achieves the result does not necessarily mean the words were nonlimiting. In re Schreiber illustrates the point: the Federal Circuit considered the claimed functional capability but concluded that a prior-art structure inherently possessed it. 128 F.3d 1473, 1477–78 (Fed. Cir. 1997).

The phrase “no patentable weight” can thus mask at least three different holdings:

•      The language is not a claim limitation at all because it merely states a purpose, use, or expected result.

•       

•      Even assuming the language limits scope, its informational or status content is not functionally integrated with the remaining claim elements and therefore cannot contribute to patentability.

•       

•      The language is limiting and patentability-relevant, but the prior art satisfies it expressly or necessarily, or an obvious modification, combination, or optimization would have produced it.

•       

Bayer supplies the second route for validation or epistemic content. Drawing on King Pharmaceuticals, Inc. v. Eon Labs, Inc., 616 F.3d 1267, 1277–79 (Fed. Cir. 2010), and In re Ngai, 367 F.3d 1336, 1338–39 (Fed. Cir. 2004), the court held that proof of clinical efficacy did not transform the process of taking the already-recited drugs at the already-recited doses. Bayer, 152 F.4th at 1404–06. The court deliberately did not collapse that conclusion into either nonlimiting language or inherency. Those holdings have different consequences for infringement, validity, prosecution history, and claim amendment. A careful analysis should state which one it means.

III.             A Taxonomy of Desired-Effect Language

Desired effects appear in several recurring forms, and identifying the form helps expose the correct question.

A.                 Intended Purpose or Use

Intended-purpose language includes formulations such as “a filter for removing contaminants,” “a method for reducing toxicity,” or “a system for efficient communication.” It is often nonlimiting when the remainder of the claim already defines a structurally or operationally complete invention and the stated purpose does not change what must be made or done.

B.                 Result Clauses

A result clause is commonly introduced by “whereby,” “wherein,” “thereby,” or “such that.” A clause stating “whereby the transaction is executed efficiently” may merely characterize the expected consequence of earlier steps. A clause requiring that “the error rate is less than one percent,” by contrast, may exclude embodiments that perform the recited steps but fail the threshold.

C.                 Functional Capability or Configuration

Functional-capability language includes “configured to,” “adapted to,” “operable to,” and “capable of.” In an apparatus claim, the language may define the physical or programmed configuration of the device. The question is frequently whether the apparatus is merely capable of the function after alteration or is presently arranged or designed to perform it.

D.                 Affirmative Efficacy, Diagnostic, or Performance Requirements

A method may require actually arresting a disease, reducing a specified adverse event, correlating a measured marker with a diagnosis, or meeting an objective performance level. Such language can give meaning to otherwise generic administration, testing, or control steps. It also can create significant proof and § 112 burdens.

E.                  E. Epistemic, Validation, or Accolade Language

Some clauses describe not what an invention does, but what is known, proven, approved, certified, or reputed about it. Examples include “clinically proven effective,” “FDA approved,” “certified,” “standard compliant,” and “award winning.” Such language may identify an evidentiary, regulatory, or reputational status rather than a technical property, operative step, or actually achieved result.

The distinction is between the effect and proof or recognition of the effect. “Reducing the incidence of stroke by twenty percent” purports to require therapeutic performance; “clinically proven effective for reducing stroke” may instead describe the status of evidence concerning an otherwise fixed regimen. In Bayer, the latter language did not change the dosages administered or the treatment performed and therefore was not functionally integrated with the claimed treatment method. 152 F.4th at 1404–06.

The classification does not control the construction. “Operating in compliance with Standard X” may incorporate concrete protocol requirements, while “certified as compliant with Standard X” may merely identify an external validation event. Construction should ask whether the phrase changes the claimed structure, conduct, or performance. If the asserted distinction instead lies in informational or status content, the conditional functional-relationship inquiry (Gate Two) asks whether that content is functionally integrated with the remaining claim elements.

F.                  Mechanism-of-Action or Explanatory Clauses

A claim may recite a biological pathway, physical principle, or causal explanation through which a known process produces its known effect. Discovering why an old process works ordinarily does not make the process new. The mechanism may be scientifically important, yet patentability generally depends on whether the claim requires a new treatment, composition, configuration, step, or result.

These categories overlap. A “wherein” clause may state an intended result, a measurable performance requirement, or an inherent mechanism. Classification is therefore a starting point, not a substitute for construing the claim.

Table 2. Separating construction significance from prior-art consequences

Observation	Construction significance	Prior-art significance
Some embodiments satisfy the other limitations but fail the effect	Strong evidence that the effect performs independent scope-narrowing work	Prior art satisfying only the other limitations may not anticipate
Every embodiment satisfying the other limitations necessarily yields the effect	May indicate redundancy, but does not by itself establish that the language is nonlimiting	Strong evidence for inherency if the prior art practices those same limitations
Separate act, present capability, or objective threshold	Supports an independent claim requirement, although syntax is not dispositive	The art must satisfy the requirement; it need not use identical words
Effect tied to recited geometry, logic, parameter, regimen, or interaction	Supports a configuration or conduct limitation	Compare the causal features; obviousness requires motivation and reasonable expectation of success
Defined test, comparator, condition, or numerical threshold	Supports an objective boundary or actual-performance requirement	Apply the same protocol; optimization requires a recognized result-effective variable
Intrinsic record treats the effect as defining the advance	Supports limiting effect but cannot override claim text	Does not by itself establish novelty, noninherency, or unexpectedness
Phrase describes proof, approval, certification, or an accolade	May define evidentiary, regulatory, or reputational status rather than the effect itself	Because this observation identifies informational or status content, apply the conditional functional-relationship inquiry before asking how the prior art satisfies the phrase

The columns deliberately separate construction from prior-art analysis. Necessity may support inherency when the prior art practices the same required structure or steps; it does not retroactively establish that the disputed phrase is nonlimiting.

IV.            Gate One: When Does the Desired Effect Limit the Claim?

A.                 Claim Placement Matters, but Grammar Is Not Dispositive

The familiar preamble cases provide useful guideposts. A preamble is more likely to limit when it supplies antecedent basis, recites essential structure or steps, gives life and meaning to the claim body, or was relied upon to distinguish the prior art. It is less likely to limit when the claim body independently describes a complete invention and the preamble merely names an intended use. Catalina Mktg. Int’l, Inc. v. Coolsavings.com, Inc., 289 F.3d 801, 808–10 (Fed. Cir. 2002). No single guidepost is controlling.

Thus, a preamble identifying a “personal recreational vehicle” did not limit claims directed to an otherwise complete marine-engine system where the body supplied the necessary structure and the intrinsic record did not make the vehicle type essential. Arctic Cat Inc. v. GEP Power Products, Inc., 919 F.3d 1320, 1327–30 (Fed. Cir. 2019). By contrast, a diagnostic purpose can be limiting when it explains what is being tested and gives the manipulative steps their reason for existence. Griffin v. Bertina held that “diagnosing an increased risk for thrombosis” limited a method of obtaining nucleic acid and assaying for a particular mutation because diagnosis was the essence of the invention and supplied meaning to “test subject” and “assaying.” 285 F.3d 1029, 1033–34 (Fed. Cir. 2002).

The same contextual treatment applies to clauses in the claim body. Moving a desired result from a preamble into a “wherein” clause does not automatically make it limiting. Nor does labeling it a separate step invariably control. Placement is evidence of function, not a formal safe harbor.

B.                 A Clause That Merely States the Consequence of Recited Limitations Is Often Nonlimiting

The Federal Circuit has repeatedly declined to give independent limiting effect to language that only describes the expected outcome of already-complete claim limitations. A “whereby” clause that “merely states the result of the limitations in the claim” adds nothing to the claim’s substance. Texas Instruments Inc. v. U.S. International Trade Commission, 988 F.2d 1165, 1172 (Fed. Cir. 1993). Similarly, “a whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited.” Minton v. Nat’l Ass’n of Securities Dealers, Inc., 336 F.3d 1373, 1381 (Fed. Cir. 2003); accord Lockheed Martin Corp. v. Space Systems/Loral, Inc., 324 F.3d 1308, 1319 (Fed. Cir. 2003).

The operative question is whether the result changes what must be done. In Bristol-Myers Squibb Co. v. Ben Venue Labs., Inc., language directed to reducing hematologic toxicity did not create a “manipulative difference” in the claimed drug-administration method. The recited dosage and infusion steps defined the treatment; the toxicity language expressed its purpose and intended result. 246 F.3d 1368, 1375–76 (Fed. Cir. 2001). The same reasoning applies when an applicant uses a functional label merely to redescribe an expressly recited quantitative condition. In Syntex (U.S.A.) LLC v. Apotex, Inc., the phrase “in a stabilizing amount” did not independently narrow a claim where stabilization was simply the result attributed to the already-specified concentration. 407 F.3d 1371, 1378 (Fed. Cir. 2005).

These decisions do not establish that outcomes are categorically irrelevant to method claims. They establish a redundancy principle: if the claim already requires a fully defined act and the disputed language does no more than announce that act’s expected consequence, the result ordinarily does not add another requirement.

C.                 A Condition Integral to the Invention Can Be Limiting

The opposite line of cases begins with the proposition that a court may not discard a condition that changes the substance of the invention. When a “whereby” clause states a condition material to patentability, it cannot be ignored. Hoffer v. Microsoft Corp., 405 F.3d 1326, 1329–30 (Fed. Cir. 2005). The clause in Hoffer required users to be able to engage concurrently in interactive data messaging. That capability was not merely an aspiration attached to the preceding network steps; it was part of the process the patent described as its central advance.

L.A. Biomedical Research Institute at Harbor-UCLA Medical Center v. Eli Lilly & Co. provides an especially useful contrast with Bristol-Myers. The claim separately required “arresting or regressing” penile fibrosis following administration of a PDE5 inhibitor. The court held that this language imposed an efficacy requirement because the claim’s dosage ceiling and minimum treatment period did not themselves ensure that fibrosis would be halted or reversed. 849 F.3d 1049, 1061–62 (Fed. Cir. 2017). The separate-step drafting was significant, though not dispositive; more important was that the claimed administration parameters did not duplicate the required therapeutic outcome.

Likewise, Allergan Sales, LLC v. Sandoz, Inc. treated detailed safety and efficacy “wherein” clauses as limiting. The clauses required a twice-daily combination treatment to match a specified comparator’s efficacy and reduce the incidence of enumerated adverse events. The specification presented those benchmarks as central benefits, the applicant relied on them to distinguish the art, and the examiner relied on them in allowing the claims. 935 F.3d 1370, 1375–76 (Fed. Cir. 2019). Chief Judge Prost’s concurrence emphasized that the clauses stated specific, measurable requirements and that the record did not establish every formulation permitted by the open-ended claims would necessarily meet them. Id. at 1377–82 (Prost, C.J., concurring).

The lesson is not that prosecution argument can transform any aspirational statement into a limitation. The claim text must bear the construction, and unilateral assertions—especially those made after an examiner has indicated allowance—cannot rewrite it. Bristol-Myers, 246 F.3d at 1375. Prosecution history is powerful when it confirms that language already appearing in the claim was used and understood to define the invention.

D.                 Treatment and Diagnostic Preambles Require Particular Care

Treatment language may do more than identify a field of use. A preamble requiring administration to a patient with a recognized therapeutic need can define the population and the purpose for which the method must be performed. Jansen v. Rexall Sundown, Inc., 342 F.3d 1329, 1333–34 (Fed. Cir. 2003). In re Xencor, Inc. addressed distinct preamble issues in two claims. Claim 8 was drafted in Jepson form, and Xencor did not dispute that its preamble was limiting; the court held that the scope-defining preamble also required written-description support. For non-Jepson claim 9, the court separately held that “treating a patient” was limiting because it gave meaning to the sole administering step and contextualized the recited increase in in vivo half-life. 130 F.4th 1350, 1358–62, 1364–66 (Fed. Cir. 2025).

But a construction victory can create a disclosure problem. Untethered to a disease or condition, Xencor’s treatment language swept across all patients and diseases, while the specification supplied no treatment example supporting that breadth. Id. The case is a reminder to ask both what the treatment phrase excludes and what its full scope affirmatively covers.

E.                  Apparatus Claims Turn on Present Structure or Configuration

For apparatus claims, a new intended use ordinarily does not make an old device patentable. If a prior-art apparatus has the same structure and can perform the recited function, describing it as “for” a new purpose generally does not distinguish it. Schreiber, 128 F.3d at 1477–78. Functional language is nonetheless permissible and must be construed; the question is what structural or configurational consequences the language carries. In re Swinehart, 439 F.2d 210, 212–13 (C.C.P.A. 1971).

“Adapted to” and “configured to” can mean more than bare theoretical capability. In In re Giannelli, a prior-art chest-press machine did not satisfy a claim to a machine “adapted to” be moved by a rowing motion merely because a user might pull on it somehow. In context, “adapted to” meant made or designed for the claimed rowing function, and the prior-art geometry was directed to a materially different exercise. 739 F.3d 1375, 1378–80 (Fed. Cir. 2014).

Functional language may also imply a structural relationship. A snowboard binding described as substantially preventing movement imposed a rigidity requirement, not simply a statement of hoped-for use. K-2 Corp. v. Salomon S.A., 191 F.3d 1356, 1363–64 (Fed. Cir. 1999). A driver “for setting” a joint required the driver and joint to be mutually adapted in the recited manner. In re Stencel, 828 F.2d 751, 754–55 (Fed. Cir. 1987).

The practical distinction is between an apparatus that could perform a function only after material alteration and one whose present structure or programming satisfies the claimed functional requirement. Drafting that identifies the configuration producing the effect—geometry, logic, material properties, component relationships, or operating parameters—makes that distinction easier to administer.

V.               Gates Two and Three: Conditional Functional-Relationship Inquiry and Prior-Art Satisfaction

A.                 When the Conditional Functional-Relationship Inquiry Applies

Bayer establishes that claim construction and patentability relevance are distinct inquiries. Claim 1 recited administering 2.5 mg rivaroxaban twice daily and 75–100 mg aspirin daily to a patient with coronary artery disease and/or peripheral artery disease to reduce the risk of myocardial infarction, stroke, or cardiovascular death; the disputed phrase required that the amounts be “clinically proven effective.” The Patent Trial and Appeal Board treated the phrase as nonlimiting and, alternatively, inherently anticipated. The Federal Circuit declined to adopt either rationale. Assuming the phrase limited the claim, the court held that clinical-proof status lacked the required functional relationship to the already-defined treatment method and therefore could not supply patentability. The court affirmed the judgment as to claims 1–4, but separately vacated and remanded as to claims 5–8 because the Board misconstrued “first product.” 152 F.4th at 1401–06, 1410.

The holding rests on the printed-matter and informational-content line of cases. That doctrine applies to information claimed for its communicative content, including instructional content. Bayer applied the rationale to clinical-proof status, a validation or epistemic distinction; the same functional inquiry can address other claimed approval, certification, or accolade status. In King Pharmaceuticals, an instruction to take a known drug with food did not distinguish a method already requiring the same administration; informing the patient about the benefit did not change how the drug was taken. 616 F.3d at 1277–79. In Ngai, newly added instructions did not make an otherwise known diagnostic kit patentable because the instructions and kit lacked the required functional relationship. 367 F.3d at 1338–39. C R Bard frames the inquiry by asking whether information merely communicates something or instead interacts with other claim elements to create new functionality in a claimed device or cause a specific action in a claimed process. 979 F.3d at 1381–82. Praxair illustrates both the positive side of Gate Two and the independence of Gate Three. Assuming the Board’s construction of “in accordance with” as “based on, or as a result of,” the recommendation was functionally integrated because claim 9 required the medical provider actually to discontinue treatment based on it; claims requiring only evaluation of the same information lacked the necessary relationship. That functional relationship entitled the recommendation to patentable weight, but it did not establish nonobviousness. As the Federal Circuit explained, “[t]hat does not end the inquiry.” The court proceeded to evaluate claim 9 as a whole and held it unpatentable as obvious over the prior art. Praxair Distrib., Inc. v. Mallinckrodt Hosp. Prods. IP Ltd., 890 F.3d 1024, 1033–37 (Fed. Cir. 2018). Thus, a control instruction that changes machine operation, a protocol incorporated into concrete steps, or information that causes claimed conduct may be functionally integrated. Information that merely reports a property, proof, or accolade ordinarily is not.

The cases often state the doctrine in terms of a “new and unobvious functional relationship.” King Pharmaceuticals, 616 F.3d at 1279. In this article’s framework, the inquiries are separated. Gate Two asks whether the informational or status content is functionally integrated with the remaining claim elements at all. Gate Three asks whether the claim as a whole, including any functionally integrated informational content or relationship, is expressly disclosed, inherent, or obvious. That allocation preserves the cases’ language without importing novelty and obviousness into the functional-relationship inquiry.

Bayer also distinguished the efficacy limitations in Allergan. The claims in Allergan encompassed an open universe of twice-daily compositions, and the specific efficacy and safety benchmarks could separate compositions inside that universe from those that failed the benchmarks. 935 F.3d at 1375–76; see id. at 1378–81 (Prost, C.J., concurring). By contrast, Bayer’s dosages and administration were fixed before the clinical-validation phrase was considered; proving that the same regimen worked did not alter the treatment. Bayer, 152 F.4th at 1405–06. The contrast is functional, not merely verbal: an objective effect may narrow what must be selected, made, or done, while proof or acclaim concerning a fully specified invention may not.

Gate Two is conditional, not a universal screen for all desired-effect language. When a disputed phrase imposes an ordinary structural, configurational, operational, or actual-performance requirement, the analysis ordinarily proceeds from construction to prior-art satisfaction without a separate printed-matter inquiry. When Gate Two does apply, the tribunal should identify the informational or status content, the remaining claim elements to which it supposedly relates, and the functionality or conduct produced by the interaction. Bayer should not become free-floating permission to disregard an inconvenient limitation merely because a tribunal considers it insufficiently connected to the invention.

The gates are analytically distinct rather than procedurally rigid. A tribunal may resolve the printed-matter and functional-relationship questions during claim construction when the inquiry turns on the meaning and relationship of the claim terms, but it should separately identify the construction and patentability propositions it is deciding. Praxair, 890 F.3d at 1033; C R Bard, 979 F.3d at 1377 n.1. A Gate Two ruling therefore need not occur in a procedurally separate stage and does not necessarily decide claim construction for every other purpose. The printed-matter cases caution against simply excising a limitation: the claim must still be considered as a whole even when functionally unrelated informational content cannot supply novelty to an otherwise anticipated claim. King Pharmaceuticals, 616 F.3d at 1277–79 (citing In re Gulack, 703 F.2d 1381, 1385–86 (Fed. Cir. 1983)). Concluding that informational or status content cannot distinguish the prior art therefore does not automatically establish that the words disappear for every other purpose. A tribunal should state separately whether the phrase limits literal scope, what it requires for infringement, and whether it creates consequences under § 112, even when it cannot supply patentability under §§ 102 or 103. Nor does failure of the conditional functional-relationship inquiry itself establish ineligibility: a claim containing functionally unrelated printed matter may remain eligible when, considered as a whole, it is not directed solely to that information. C R Bard, 979 F.3d at 1383–84.

B.                 Express Disclosure, Inherency, and Newly Recognized Effects

Once a desired effect survives any applicable Gate Two inquiry—or when Gate Two does not apply—anticipation requires the prior art to disclose the patentability-relevant requirement along with every other claim element, arranged as claimed. When informational or status content fails Gate Two, that content cannot distinguish the prior art, but Gate Three still tests the remaining patentability-relevant limitations. C R Bard, 979 F.3d at 1384–85. The reference need not use the claim’s words. It may satisfy the effect expressly, or the effect may be inherent in what the reference teaches. Net MoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359, 1369–71 (Fed. Cir. 2008).

Inherency demands necessity, not possibility or probability. A missing characteristic is inherent only when it is necessarily present in, or inevitably results from, practicing the prior-art disclosure. In re Oelrich, 666 F.2d 578, 581 (C.C.P.A. 1981). A result that may occur under selected conditions is insufficient. Nor does scientific plausibility establish that every embodiment required by the reference produces the result.

During examination, however, an applicant may face a burden of production when the Office identifies a prior-art product or apparatus that appears identical or substantially identical. In Schreiber, the prior-art conical spout was structurally capable of dispensing popcorn in the claimed manner even though it had been disclosed for dispensing oil. Once the examiner established a sound basis for believing the structures were the same, the applicant was required to show that the prior-art device lacked the asserted capability. 128 F.3d at 1477–78; see MPEP § 2112. That procedural shift does not dilute necessity; it reflects who has better access to contrary evidence after a prima facie showing. In district court, the patent remains presumed valid, and invalidity must be proved by clear and convincing evidence. 35 U.S.C. § 282(a); Microsoft Corp. v. i4i Ltd. Partnership, 564 U.S. 91, 95 (2011).

A patentee generally cannot make an old process new by discovering an unappreciated consequence of performing it. Bristol-Myers explained that newly discovered results of a known process directed to the same purpose are inherent in that process. 246 F.3d at 1376. The inquiry concerns what necessarily happened, not whether the prior-art author recognized it. Thus, in Persion Pharmaceuticals LLC v. Alvogen Malta Operations Ltd., pharmacokinetic limitations did not distinguish prior art administering the same formulation in the same manner to the relevant patient population because the recited concentration profile necessarily resulted. 945 F.3d 1184, 1190–91 (Fed. Cir. 2019). The profile was a real claim requirement, but not a new fact.

The same principle applies to newly discovered mechanisms. In In re Couvaras, the applicant claimed mechanistic steps through which two known antihypertensive agents produced their known blood-pressure-lowering effect. Because the mechanism naturally flowed from co-administration, reciting it did not overcome the prima facie case of obviousness—even if the mechanism itself had been unexpected. 70 F.4th 1374, 1380–81 (Fed. Cir. 2023). Patentability ordinarily lies in a new treatment, composition, regimen, configuration, or result, not merely in a later explanation of why a known treatment achieves its known result.

C.                 Inherency, Obvious Modification, and Routine Optimization Require Different Proof

Three routes are often blurred. Inherency asks whether the missing feature necessarily exists or inevitably results when the prior art is practiced. Obvious modification or combination asks whether a skilled artisan had reason to make the proposed change and reasonably expected it to succeed. Routine optimization asks, as part of obviousness, whether the art recognized a variable as affecting the relevant result and whether selecting its value would have been routine on the factual record. Calling an effect “natural” or “predictable” does not substitute for the showing required by the chosen route.

Inherency may supply a missing limitation in an obviousness analysis, but its use must be carefully circumscribed. PAR Pharmaceutical, Inc. v. TWI Pharmaceuticals, Inc., 773 F.3d 1186, 1194–96 (Fed. Cir. 2014). The claimed effect must be the natural and necessary result of the combination proposed by the prior art. A showing that the effect was likely, common, or one possible outcome is not enough.

That rule should not be confused with reasonable expectation of success. Obviousness may rest on what a skilled artisan would have been motivated to do and reasonably expected to achieve even if the art did not establish inevitability. But when a challenger invokes inherency to supply an otherwise missing limitation, necessity remains the standard. The decisionmaker should identify which proposition the evidence proves: inevitability of an unstated result, reason to pursue a modification or combination, or reasonable expectation that the proposed course would achieve the claimed requirement.

A claimed effect also may follow from routine optimization of a variable the art recognized as affecting that effect. In re Applied Materials, Inc., 692 F.3d 1289, 1295–98 (Fed. Cir. 2012). The doctrine is not boundless. It presupposes a recognized result-effective variable and an adequate factual basis for concluding that optimization would have been routine; it does not authorize treating every unclaimed mechanism as a knob waiting to be turned. In re Antonie, 559 F.2d 618, 620 (C.C.P.A. 1977).

D.                 Unexpected Results Require a Nexus to the Merits

Evidence that an effect was unexpected can rebut an obviousness case, but the evidence must be tied to the claimed invention and commensurate with its scope. A surprising result shown for one species may carry little weight for a claim covering a large functional genus. Likewise, an unexpected mechanism does not establish an unexpected therapeutic benefit where the benefit itself was known. Couvaras, 70 F.4th at 1380–81.

Bayer adds a logically prior nexus question. The patentee’s unexpected-results evidence concerned clinical proof of the fixed regimen’s efficacy. Because that proof was functionally unrelated to the merits of the claimed treatment process, the evidence lacked the required nexus and could not carry patentable significance. 152 F.4th at 1409–10; see Volvo Penta of the Americas, LLC v. Brunswick Corp., 81 F.4th 1202, 1210 (Fed. Cir. 2023); In re Huai-Hung Kao, 639 F.3d 1057, 1068, 1074 (Fed. Cir. 2011). Unexpectedness is therefore not an independent route for converting validation, reputation, or a newly discovered explanation into an inventive feature.

The cleanest record distinguishes four propositions: the claim requires the asserted feature; when Gate Two applies, the informational or status content is functionally integrated with the remaining claim elements; the prior art does not expressly or necessarily satisfy the patentability-relevant requirement and does not render it obvious; and comparative evidence shows an unexpected result with a nexus to the claimed advance. Each applicable proposition needs its own legal and evidentiary support.

E.                  The Ultimate Prior-Art Question: Does the Result Add a Patentability-Relevant Difference Not Disclosed, Inherent, or Obvious?

A patentability-relevant effect is most likely to distinguish the art when the prior art does not expressly teach it, the same acts or structure do not necessarily produce it, and a skilled artisan would not have had reason and reasonable expectation to modify the art to obtain it. L.A. Biomedical demonstrates the analysis. Because the claimed dosage ceiling and minimum duration did not necessarily arrest or regress fibrosis, the efficacy requirement could not simply be read out or presumed inherent. 849 F.3d at 1061–62, 1067–68.

The converse is equally important. If the claim recites the same structure, composition, patient population, and operating conditions as the prior art, adding either an inevitable result or functionally unrelated proof of that result ordinarily will not save it. The applicant must identify a patentability-relevant difference: a configuration that causes the performance, a step that produces the result, a parameter range the art did not disclose or render obvious, or evidence that the asserted effect does not inevitably follow from the prior-art teaching.

VI.            Applying the Doctrine Across Claim Types

The significance of a claimed effect depends partly on the statutory class of the claim. The same words—“configured to reduce noise,” “reducing noise,” or “a composition that reduces noise”—may respectively describe capability, a required act or outcome, or a functionally defined class. That difference affects construction, prior-art analysis, validity, and infringement proof.

A.                 Apparatus and System Claims: Tie Capability to Concrete Implementation

In an apparatus claim, result language ordinarily matters when it requires the claimed structure to possess a particular capability or configuration. A controller “configured to maintain a target temperature,” for example, may exclude controllers that cannot perform that function. But the phrase does not necessarily require the accused or prior-art apparatus to be operating at the target temperature at the relevant moment. The practical inquiry is whether the effect implies a meaningful configuration or merely states the purpose for which an otherwise complete apparatus might be used.

Claims are generally better positioned when they connect the effect to identified structure and interaction. In PowerBlock Holdings, Inc. v. iFit, Inc., the Federal Circuit held mechanical claims patent eligible because they did more than claim the general result of automated weight adjustment. They recited nested weight plates, a movable selector, an electric motor operatively connected to the selector, and physical movement of the selector to couple selected plates to a dumbbell. 146 F.4th 1366, 1371–73 (Fed. Cir. 2025). The claimed result was the product of a recited mechanical arrangement, not a substitute for one.

That distinction also bears on infringement. A capability limitation may permit proof through design documents, source code, standardized testing, or the accused product’s normal operating configuration. A limitation requiring actual achievement of the result may instead require proof that the result occurred under the claim’s conditions. Drafters should decide which proposition they intend to claim and use different claim sets when both are commercially important.

B.                 Method Claims: Distinguish the Act from Its Consequence

Method claims present a sharper distinction between performing a step and describing what follows from it. “Adjusting a valve to maintain pressure below 50 psi” may require conduct directed to the pressure constraint. “Adjusting a valve, thereby improving safety” may describe only the hoped-for consequence. Grammar is not dispositive, but a measurable endpoint that determines when or how a step is performed is more likely to affect claim scope than a clause that merely praises the completed process.

A result that is part of the method creates corresponding enforcement consequences. If a claim requires “reducing an error rate below one percent,” infringement may depend on the test population, baseline, measurement interval, and statistical treatment. If the effect occurs only after another party uses the product—or only within a patient—the patentee must account for who performs each step and what evidence proves the endpoint. A result limitation can therefore strengthen patentability while making infringement more expensive to establish.

C.                 Treatment Claims: Define the Patient, Indication, Regimen, and Endpoint

Treatment claims illustrate both the value and danger of desired-effect language. For non-Jepson claim 9, Xencor held “treating a patient” limiting, yet affirmed a written-description rejection because the broad phrase covered all patients and diseases without supporting treatment disclosure. 130 F.4th at 1358–62.

Teva Pharmaceuticals International GmbH v. Eli Lilly & Co. supplies a record-dependent contrast. The appeal followed a jury verdict and post-trial judgment as a matter of law. On that record, a reasonable jury could find the underlying antibody genus well known, humanization routine, and the members understood to work for the focused claimed use of reducing or treating headache. The Federal Circuit therefore reversed the judgment as a matter of law of inadequate written description and enablement. 172 F.4th 1367, 1374–81 (Fed. Cir. 2026). Teva is not a broad substantive safe harbor from Amgen; its outcome depends on the verdict, the governing standard of review, the focused method of use, and the jury-supportable state-of-the-art findings.

Wyeth LLC v. AstraZeneca Pharmaceuticals LP supplies a recent counterpoint. The Federal Circuit rejected the patentee’s contention that the district court had altered the unchallenged pretrial construction of “unit dosage” after the verdict. That construction adopted the specification’s express definition of a “unit dosage” as a predetermined quantity calculated to produce a desired therapeutic effect. Reading it together with the requirements of daily administration to a patient, the court held that the claims demanded a repeatable patient-dosing regimen calculated to produce a therapeutic effect, rather than merely identifying compounds exhibiting in vitro EGFR inhibition. The court treated the postverdict elaboration as a permissible clarification of what the original construction inherently required. The court nevertheless affirmed the judgment as a matter of law that the claims were not enabled because the specification supplied no working patient-dose examples or guidance bridging the disclosed in vitro activity to daily dosages calculated to produce a therapeutic effect in patients across the full scope of claimed irreversible EGFR inhibitors. The decision thus illustrates that treatment-effect language may perform genuine scope-defining work while exposing a corresponding failure of full-scope enablement. Wyeth LLC v. AstraZeneca Pharms. LP, No. 2024-2325, slip op. at 9–15, 18–19 (Fed. Cir. July 9, 2026).

D.                 Composition and Product Claims: Performance Boundaries Can Define a Vast Genus

For a composition or product, a desired effect may define membership in the claimed class: every antibody that binds and blocks a target, every filter that meets a performance factor, or every material that achieves a stated strength. Such language is not necessarily nonlimiting. Its danger is often the opposite: it may make the claim so broad that the specification does not support or enable the full class.

In Amgen Inc. v. Sanofi, the claims covered a genus of antibodies defined by two functions—binding specified PCSK9 residues and blocking PCSK9 from binding LDL receptors. The specification identified twenty-six antibodies but left scientists to generate and screen large numbers of additional candidates. The Supreme Court held that the specification must enable the full scope claimed and that a trial-and-error research assignment did not do so. 598 U.S. 594, 610–15 (2023).

Brita LP v. International Trade Commission applied the same scope-sensitive principle outside biotechnology, affirming both written-description and enablement determinations. The claims broadly covered filter media that achieved a specified FRAP performance factor, but only carbon-block filters were shown to satisfy the requirement, and the disclosure did not teach skilled artisans how to achieve the claimed performance with other filter media. 156 F.4th 1326, 1333–45 (Fed. Cir. 2025). A numerical effect can therefore provide a crisp claim boundary while leaving an unsupported genus inside that boundary.

E.                  Software, AI, and Control Claims: Claim the Rule or Architecture, Not Only the Objective

Software and control claims often recite goals—optimizing a resource, improving relevance, reducing error, or generating an accurate output—while leaving the operative rule unspecified. That drafting can fail at several levels. A generic processor may already be capable of the function; the result may be an abstract idea; or the specification may not teach the full range of implementations that the functional language covers.

Durable claims identify the data transformation, control loop, model architecture, objective function with operative constraints, ordered processing steps, or hardware interaction that produces the effect. A performance metric can remain useful, especially in a dependent claim, but it should confirm a technical implementation rather than replace it.

AI performance limitations require particular attention to the conditions under which the asserted result is measured. Accuracy, error rate, robustness, or bias may depend on the training corpus, evaluation dataset, model version, random seed, confidence interval, and deployment environment. Training limitations also differ from inference-time constraints: a model trained by a specified process is not necessarily the same claim as a deployed model required to perform particular operations. A claim requiring a model to achieve a specified result should therefore identify the operative architecture, training or inference constraints, and a reproducible evaluation protocol rather than treating an aggregate performance score as self-defining. For a performance-defined model genus, the specification should also support the range of model architectures, datasets, and operating conditions encompassed by the claimed metric.

VII.         Patent Eligibility, Section 112, and Enforcement Risks

Receiving limiting effect is not the end of the analysis. The more work a desired effect performs in defining the invention, the more closely the claim must be examined under 35 U.S.C. §§ 101 and 112.

A.                 Section 101: Claiming the Technical Result Without the Technical Solution

Result-oriented claiming can create an eligibility problem when the asserted advance is an abstract idea or natural law and the claim monopolizes the result without reciting a concrete way to achieve it. In American Axle & Manufacturing, Inc. v. Neapco Holdings LLC, the Federal Circuit held claim 22 ineligible where, as construed, it required tuning a liner’s mass and stiffness to attenuate vibration but did not limit the claim to a particular tuning technique. The panel characterized the claim as invoking Hooke’s law to obtain the desired result; it vacated and remanded as to a differently worded claim. 967 F.3d 1285, 1294–99 (Fed. Cir. 2020). The fractured and heavily contested decision should be applied to its facts, but its warning about result-only drafting is clear.

The Federal Circuit’s 2025 and 2026 decisions sharpen the contrast. PowerBlock upheld a claim tied to a particular motor-driven mechanical arrangement. 146 F.4th at 1371–73. In Constellation Designs, LLC v. LG Electronics Inc., “optimization claims” covering every way to optimize a signal constellation for parallel-decode capacity were ineligible because they stated the distinguishing feature as a result without reciting how to obtain it. Claims to specific nonuniform constellations with identified point relationships were eligible because they claimed a concrete technological implementation. 174 F.4th 888, 901–06 (Fed. Cir. 2026).

The drafting lesson is not that functional language is categorically suspect. It is that the claim should recite the technical architecture, transformation, rule set, control sequence, or other concrete action that produces the result—particularly when the result is itself the alleged advance.

B.                 Section 112(a): Support and Enable the Scope Created by the Effect

Written description asks whether the disclosure reasonably conveys possession of the claimed invention; enablement asks whether a skilled artisan can make and use its full scope without undue experimentation. Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1349–52 (Fed. Cir. 2010) (en banc); Amgen, 598 U.S. at 610–15. A desired-effect limitation can enlarge both burdens by collecting structurally diverse embodiments into a single functional class.

Amgen requires attention not merely to the number of examples but to whether the specification discloses a principle, common quality, or sufficiently reliable guidance spanning the claimed class. Brita similarly warns that declaring a performance criterion applicable to many architectures does not demonstrate possession of architectures that the inventors did not make and could not predict. 156 F.4th at 1333–45. Juno Therapeutics, Inc. v. Kite Pharma, Inc. reinforces the written-description risk where a broad functional genus is supported by few examples and no way to identify the additional species that perform the claimed function. 10 F.4th 1330, 1335–39 (Fed. Cir. 2021).

Teva should not be read as a substantive safe harbor from Amgen. Under the post-verdict judgment-as-a-matter-of-law posture, the court held that a reasonable jury could credit evidence that the antibody genus was already well understood, humanization was routine, and the genus worked across the focused claimed use. 172 F.4th at 1374–81. That record shows how state-of-the-art knowledge may support a focused method-of-use claim; it does not excuse a patentee from enabling and describing the full scope actually claimed.

Wyeth likewise confirms that skilled-artisan knowledge may supplement, but cannot substitute for, the specification’s missing technical bridge from disclosed in vitro activity to the patient-level dosing regimen required across the full scope of a functionally defined treatment class. Wyeth, slip op. at 13–15, 18.

C.                 Section 112(b): Give the Result Objective Boundaries

An effect must inform skilled artisans of claim scope with reasonable certainty. Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898, 910 (2014). In Datamize, LLC v. Plumtree Software, Inc., the Federal Circuit found “aesthetically pleasing” indefinite because the patent supplied no objective standard for deciding what satisfied the term. 417 F.3d 1342, 1350–52 (Fed. Cir. 2005), abrogated as to the governing definiteness formulation by Nautilus, 572 U.S. 898. Subjectivity is not automatically fatal; examples, operational criteria, and an established measurement framework can provide objective boundaries. Sonix Technology Co. v. Publications International, Ltd., 844 F.3d 1370, 1377–80 (Fed. Cir. 2017).

For quantitative effects, the specification should identify the test method, equipment, sample preparation, environmental conditions, reference baseline, statistical treatment, and tolerance that matter. A number without a reproducible measurement protocol can generate as much uncertainty as a qualitative adjective.

D.                 Section 112(f): “Configured To” Is Not an Automatic Safe Harbor

Functional language may invoke § 112(f). Omitting the word “means” creates a rebuttable presumption against § 112(f), but that presumption can be overcome when a generic placeholder modified by functional language fails to connote sufficiently definite structure. Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1348–52 (Fed. Cir. 2015) (en banc in relevant part). “Configured to” is not automatically means-plus-function language; it may, however, link a nonce term to a function. The MPEP’s § 112(f) examination framework similarly asks whether the limitation uses a generic placeholder, couples it to functional language, and fails to recite sufficient structure or acts. MPEP § 2181.

If § 112(f) applies, the limitation is confined to corresponding structure, material, or acts disclosed in the specification and statutory equivalents. Failure to disclose structure linked to the entire function can render the claim indefinite; for a specific computer-implemented function, that often requires a disclosed algorithm. “Means for achieving the desired effect” may therefore narrow a claim dramatically—or invalidate it—rather than provide broad functional coverage.

E.                  The Practical Patentability Squeeze

Desired-effect language produces a recurring, although not formally doctrinal, patentability squeeze. If the effect is merely aspirational, it may do no work against the prior art. If it is a genuine functional limitation, the prior art may inherently possess it. If drafted to cover every mechanism that achieves the effect, it may encounter §§ 101 and 112. If drafted as an actual measured outcome, it may impose demanding infringement-proof requirements. Adding concrete structure or steps improves validity but creates clearer design-around paths.

The best response is layered claiming and matching disclosure. Claims should separately protect the mechanism, the operational method, and—where commercially important—the objectively measured result. The specification should connect those layers through causal explanations, representative embodiments, alternatives, unsuccessful examples where useful, and reproducible test protocols. That approach does not eliminate the squeeze, but it makes the claimed effect an engineered limitation rather than a litigation-dependent aspiration.

VIII.       Conclusion

A desired effect is not categorically entitled to, or excluded from, patentable weight. It limits when the properly construed claim requires the invention to possess a capability, embody a configuration, perform additional conduct, achieve an objective result, or carry some other defined status. An ordinary structural, configurational, operational, or actual-performance requirement ordinarily proceeds directly to the prior-art analysis. When the phrase instead asserts informational or status content, then even assuming it limits scope, it can supply patentability only if that content interacts functionally with the remaining claim elements. Every patentability-relevant requirement distinguishes the prior art only when it is not expressly disclosed or necessarily present and would not result from an obvious modification, combination, or optimization supported by the requisite motivation and reasonable expectation of success and, for optimization, a recognized result-effective variable.

The practical discipline is to resist shorthand. “Intended result,” “functionally unrelated information,” and “inherent property” describe different issues. A sound analysis identifies the governing construction standard and claim requirement first, applies the conditional functional-relationship inquiry when the doctrine is triggered, and then applies the correct prior-art doctrine before confronting the separate validity, eligibility, and enforcement consequences. Gate Two is neither an automatic infringement exemption nor, standing alone, an ineligibility holding. The destination can matter—but only if the claim requires arrival there and the prior art did not already travel the same route. When the claimed “destination” is merely knowledge, proof, approval, or acclaim, it must also do more than describe the journey from the outside.