For the first time since the AI race began, more American businesses are paying for Anthropic's Claude than for OpenAI's ChatGPT.

Adoption of Anthropic rose 3.8% in April to 34.4% of businesses, according to the May 2026 release of the Ramp AI Index. OpenAI's adoption fell 2.9% to 32.3%. Overall AI adoption among businesses rose 0.2 percentage points to 50.6%.

The crossover — published Tuesday by Ramp, the corporate card and finance automation platform that tracks spending patterns across more than 50,000 U.S. businesses — marks the culmination of a yearlong surge by Anthropic that few in the industry predicted. Anthropic has quadrupled its business adoption over the past year, while OpenAI grew its business adoption by only 0.3%.

But the same report that crowns a new market leader also warns that Anthropic's position may be more fragile than it appears — threatened by escalating costs, compute constraints, and the very token-based pricing model that has fueled the company's extraordinary revenue growth.

Anthropic's share of U.S. business adoption surpassed OpenAI's for the first time in April, capping a rapid ascent from less than 1 percent in mid-2023 to 34.4 percent. Overall AI adoption among businesses crossed 50 percent the same month. (Source: Ramp AI Index)