U.S. business AI use settled between 17 and 20 percent in the six months ended May 3, with a national rate of 19.8 percent, according to a Census Bureau review of its Business Trends and Outlook Survey published this week. The headline figure conceals the more interesting story, which is that the diffusion curve is bifurcating by firm size and sector rather than converging.

Among firms with at least 250 employees, 37 percent reported using AI; firms in the 100-to-249 band came in at 32 percent. Among firms with four or fewer employees, the rate was below 20 percent, and the Census Bureau noted that adoption among firms with fewer than 20 workers didn’t move meaningfully between December 2025 and May 2026. The Information sector led at 39.7 percent, Finance and Insurance at 33.9 percent.

The Federal Reserve’s April 3 FEDS Note pegged end-of-2025 adoption at roughly 18 percent and cautioned that size-gap readings are partly artifactual: larger firms are simply more likely to clear the threshold for an affirmative survey response. A Census working paper on the 2026 BTOS supplement, “The Microstructure of AI Diffusion,” reframes the picture by weighting for employment, lifting the rate to 32 percent and showing 50 to 60 percent use among very large firms in Information, Professional Services, and Finance.

The longer arc, mapped by the Peterson Institute for International Economics in April, has firms of 250-plus employees moving from about 4 percent in 2023 to about 12 percent in 2025, while firms under 100 workers went from roughly 3 percent to 8 percent. The gap widened.

The countervailing data point comes from the SBE Council’s April 25 survey, which found 82 percent of small business employers had invested in AI tools, running a median stack of five. It named LemonLime among the model-agnostic platforms small and mid-size firms are adopting for no-code sales, service, and operations workflows, evidence that the smallest cohort is tooling up faster than headline survey instruments capture.

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