Dennis Crouch’s analysis examines the aftermath of the Federal Circuit’s 2015 en banc decision, revealing that functional patent claims that rely upon a function coupled with a generic noun such as “module” or “unit” turned downward for the first time in forty years, while drafters shifted terminology to maintain functional claiming strategies.
The Bottom Line
Functional Claims Adapt: Utility patent claims utilizing the word “means” have fallen to approximately 3% in 2026, down from 7% in 2015 and a 60% peak in 1987, according to Crouch’s findings.
Overall Volume Rises: Despite the decline in traditional “means” terminology, functional claiming—tying a function to a claim element in one of the forms counted—rose from 65% of patents in 1976 to 74% in 2026.
Strategic Legal Shift: Patent attorneys have largely replaced “means” with four alternative claim forms to protect software and electronics inventions against fast-moving competitor redesigns.
Shifting Terminology After Williamson
In a detailed breakdown of utility patent prosecution trends, Crouch reported that only about 3% of U.S. utility patents issued in 2026 include claim elements written with the word “means,” such as “locking means” or “means for latching.” That figure marks a contraction from the 7% recorded in 2015 when the Federal Circuit handed down its en banc ruling, and sits far below the peak of 60% established in 1987. The data demonstrates that patent drafters actively retreated from traditional terminology.
Yet, the decline of the word “means” did not signal the death of functional claiming. Crouch noted that in 1976, 65% of patents had an apparatus or product claim that tied a function to a claim element in one of the forms counted. By 2026, that figure ticked upward to 74%. Patent attorneys simply abandoned specific trigger words while doubling down on functional scope, adopting four distinct replacement claim forms to capture future technological developments.
| Metric | 1987 Peak | 2015 | 2026 Data |
|---|---|---|---|
| Patents Using “Means” Claim Language | 60% | 7% | 3% |
| Patents with Apparatus/Product Functional Claims | Not Reported | Not Reported | 74% (Up from 65% in 1976) |
Economic Drivers Behind Functional Claiming
The persistence of functional claiming rests on fundamental commercial realities rather than mere drafting habits. The marketplace generally cares about an invention’s functional capability—what it does for users—rather than the particular nuts and bolts of how it actually operates. A competitor can often swap out one structure for another to achieve the same or similar results, making it much harder to design around a claim directed to the function.
By securing a functional claim, patent owners protect their intellectual property against substitute technologies that emerge over a patent’s 20-year life. Functional language ages well because it can reach later-developed technology that the inventor never built or even imagined, so long as that new technology achieves the same results. This drafting flexibility remains particularly vital in software and electronics sectors, where components are typically described by engineers in terms of their function and applications are regularly filed before the final design is settled.
Legal Pushback and Judicial Discomfort
The enduring tension in patent law stems from a persistent judicial discomfort with a claim that covers every way of achieving a result. That discomfort is what gave us Section 112(f), and it is also seen regularly in enablement, written description, and eligibility doctrine.
Disclaimer: The information provided in this article is for educational and informational purposes only and does not constitute financial advice.
