“In the three years before Williamson, district court litigants had a 24% success rate in making arguments that claim terms lacking ‘means for’ language are subject to Section 112(f) (25 out of 104 cases). In the three years after Williamson, district courts issued 171 opinions addressing terms lacking ‘means for’ language and Section 112(f) …representing a 64% increase [in the frequency of such arguments].”

Coverage of the Senate Judiciary Subcommittee on Intellectual Property hearings on proposed amendments to the Patent Act has trumpeted the possibility that Congress will undo the Alice test for Section 101 eligibility. Many stakeholders have commented on the benefits this could bring to patentees. But if this comes to pass, accused infringers won’t cease bringing early validity challenges—they’ll instead shift their focus from Section 101 to other grounds. Testimony before the Senate and the data on recent district court decisions strongly suggest that Section 112(f) will emerge as the preeminent ground for early validity challenges.

Codifying Williamson

In addition to amending Section 101, the proposed amendments would codify the functional-claiming standard which the en banc Federal Circuit announced in Williamson v. Citrix, 792 F.3d 1339 (Fed. Cir. 2015). As former USPTO Director David Kappos testified before the Subcommittee, the proposed legislation stands to decrease invalidity challenges under Section 101, while increasing invalidity challenges under Section 112:

The draft [amendment] will productively redeploy judicial and USPTO resources to the real issues affecting patentability, returning Section 101 to its proper role as a coarse filter for screening claims manifestly lacking any practical utility through human intervention, and leaving the fine grained assessment of patentability to sections 102, 103, and 112…. One constructive approach is further strengthening Section 112.

And David Jones, Executive Director of the High Tech Inventors Alliance, testified that the Section 101 “propos[al] fundamentally changes … the statutory provision defining the types of inventions that may be patented.” He further testified that the Section 112(f) proposal “will eliminate lingering arguments about the effect of inclusion or omission of the words ‘means for’ and whether particular terms should be interpreted as functional in the wake of Williamson.”

Under Williamson, patent claims lacking specific “means for” language no longer enjoy a “strong” presumption against the applicability of Section 112(f). Courts must instead focus on whether claim limitations recite a function complemented by a “nonce” word (e.g., a “module,” “mechanism,” “device,” or another generic “black box” comparable to “means for” or “step for”) without sufficient structure to perform the function. If so, Section 112(f) narrowly restricts the claimed function to its corresponding patent-disclosed structure (and equivalents), or renders it invalid as indefinite if the function isn’t clearly linked to such a structure.

A Look at the Data



The objective data on Williamson’s impact so far shows that its influence will likely grow in a landscape of fewer Section 101 challenges under Alice. Williamson’s lower functional-claiming standard has caused a spike in the frequency and success rate of arguments that claim terms lacking “means for” language are subject to Section 112(f). In the three years before Williamson, district-court litigants had a 24% success rate in making such arguments (25 out of 104 cases). Courts decided the vast majority of these arguments at claim construction, and a handful on summary judgment. And all 104 decisions cited the strong presumption that Section 112(f) doesn’t apply.



By contrast, district courts issued 171 opinions addressing terms lacking “means for” language and Section 112(f) in the three years after Williamson, again mostly in connection with claim construction. This represents a 64% increase in how often parties argued that terms lacking “means for” language were subject to Section 112(f)—an especially dramatic change considering that there was a 26% decline in new patent infringement cases during the same period. Parties were also 75% more successful in making these Section 112(f) arguments, as shown below.

These trends are likely to continue or accelerate if Congress undoes the Alice test for Section 101 challenges and codifies Williamson’s lower functional-claiming standard for Section 112(f). At the conclusion of the hearings, Senator Thom Tillis emphasized the “need to further enhance our proposals for Sections 112 so that vague business methods and generic computer claims can’t pass muster and be weaponized against small businesses, start-ups, and entrepreneurs.” So if Alice withers, the Williamson challenges are likely to blossom.