By Eli Tan

Reporting from San Francisco

Sept. 4, 2026

AT&T turned to artificial intelligence models from Anthropic and OpenAI in recent years to help with customer service, call transcription and coding. The A.I. models charged fees and were “closed,” which meant the A.I. companies did not share their underlying code.

This year, AT&T changed course.

As A.I. costs skyrocketed, Andy Markus, the company’s chief data and A.I. officer, looked for cheaper alternatives. He landed on “open” models, which can be downloaded and modified without payment or approval.

By May, open models accounted for 20 percent of AT&T’s A.I. use. That has since risen to 40 percent and may jump to 60 percent in the coming months, Mr. Markus said in an interview.

“We believe it could go much, much higher,” he said, adding that AT&T was saving up to 80 percent on A.I. costs compared with earlier this year.

Open-source artificial intelligence has become all the rage in corporate America. Like AT&T, companies such as Airbnb and Deloitte are also turning to open A.I. models that are easy to customize and cheaper to use. Last month, open models accounted for 58 percent of A.I. use, up from 10 percent a year ago, according to U.S. user data from OpenRouter, a platform that lets people choose different A.I. models to complete tasks.

On Thursday, the chip maker Nvidia announced it was buying Hugging Face, a library of open A.I. models, for $12.9 billion, another sign of the technology’s importance.