Illinois inventionINDEX September 2026: 1.33% (B grade)

The inventionINDEX measures innovation output by comparing GDP growth with patent production growth.

Anything over C grade is positive sentiment; anything under C is negative outlook/sentiment. Using that sentiment, it is possible to observe trends over time, and also compare states/countries. In doing so, we can predict which states have the best chance to recover economically from the pandemic (or any other economic incident that may occur).

Historical Illinois inventionINDEX Scores

The Illinois inventionINDEX score for the past 12 months is shown in the table below.

The Illinois inventionINDEX reached 1.33% in September 2026, earning a B rating and marking a distinct stabilization after several volatile months. This metric aligns closely with the overall 61-month historical average of 1.34%, signaling that the state innovation engine has returned to its baseline equilibrium. Throughout 2026, monthly scores fluctuated from a low of 0.85% (D+) in April to a high of 1.38% (B) in June, yielding a year-to-date average of 1.13%. While this year-to-date figure sits below the full-year averages of recent years—1.27% in 2025, 1.39% in 2024, 1.45% in 2023, and 1.47% in 2022—the latest September score demonstrates a healthy upward trajectory from the summer trough of 0.97% in July 2026.

A broader examination of the historical dataset reveals significant cycles in regional inventive performance across the 60-month horizon. The index recorded its peak activity in October 2023 with an extraordinary score of 3.00% (A+), followed by other high-water marks such as August 2023 at 2.25% (A+) and March 2022 at 2.20% (A+). Conversely, the index experienced notable pullbacks in July 2023 at 0.43% (F) and September 2021 at 0.57% (F). When placed in this historical context, the recent recovery from April 2026 (0.85%) to September 2026 (1.33%) reflects a resilient rebound, moving past mid-tier ratings toward upper-level sustainability.

Achieving higher scores and elevated ratings yields substantial positive outcomes for the Illinois economy. When the inventionINDEX climbs into the B and A tiers, it reflects robust intellectual property creation, surging patent applications, and heightened venture capital deployment into regional startups. Higher ratings serve as a strong beacon to institutional investors, corporate research partners, and high-skilled talent, signaling a fertile environment for technological commercialization. Moreover, sustained high performance accelerates market expansion across key sectors like technology, biotechnology, and advanced manufacturing, reinforcing the reputation of Illinois as a premier hub for Midwestern innovation.

On the other hand, sustained lower scores and depressed ratings carry significant negative implications for the innovation ecosystem. Months characterized by D or F ratings, such as July 2023 or April 2026, point toward contraction in new enterprise formation, delayed technology transfers, and cautious capital allocation by private investors. Prolonged weakness in the index risks eroding regional competitiveness, potentially leading to talent migration toward higher-performing market clusters and reduced commercial activity. Maintaining scores consistently at or above the historical mean of 1.34% remains critical to maintaining momentum, protecting research investments, and ensuring long-term economic growth.

Discussion:

In September, the Illinois inventionINDEX scored a positive sentiment which was higher than the previous year’s average and outperformed the upward trend for the year. This is in contrast to the prior 12 months, which experienced a slight downward trend.

As the economy continues to stabilize in the post-pandemic era, it remains uncertain whether any backlog of applications still exists or if the department has returned to normal processing timelines. The inventionINDEX could also be affected by lingering consequences from the pandemic, such as company closures, reduced workforces, and limited R&D capabilities, which may still be impacting current operations.

Learn More:
Are you thinking of patenting any of your bright ideas? Did you know your research work could be eligible for the R&D Tax Credit and you can receive up to 14% back on your expenses? To find out more, please check out our free online eligibility test.

Swanson Reed’s Illinois office provides R&D tax credit consulting and advisory services to Chicago, Aurora, Rockford, Joliet, Naperville, Springfield, Peoria, Elgin, Waukegan, Champaign, Bloomington, Decatur, Evanston, Des Plaines, Berwyn, Wheaton, Carbondale, Mount Prospect, Oak Lawn and Skokie

Feel free to book a quick teleconference with one of R&D tax specialists if you would like to learn more about R&D tax credit opportunities.

Who We Are:

Swanson Reed is the largest Specialist R&D tax credit advisory firm in the United States. With offices nationwide, we are one of the only firms globally to exclusively provide R&D tax credit consulting services to our clients. We have been exclusively providing R&D tax credit claim preparation and audit compliance solutions for over 30 years.

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