An OpenAI researcher who worked on GPT-4.5 had their green card denied

Kai Chen, a Canadian AI researcher working at OpenAI who’s lived in the U.S. for 12 years, was denied a green card, according to Noam Brown, a leading research scientist at the company. In a post on X, Brown said that Chen learned of the decision Friday and must soon leave the country.

“It’s deeply concerning that one of the best AI researchers I’ve worked with […] was denied a U.S. green card,” wrote Brown. “A Canadian who’s lived and contributed here for 12 years now has to leave. We’re risking America’s AI leadership when we turn away talent like this.”

Another OpenAI employee, Dylan Hunn, said in a post that Chen was “crucial” for GPT-4.5, one of OpenAI’s flagship AI models.

Green cards can be denied for all sorts of reasons, and the decision won’t cost Chen her job. In a follow-up post, Brown said that Chen plans to work remotely from an Airbnb in Vancouver “until [the] mess hopefully gets sorted out.” But it’s the latest example of foreign talent facing high barriers to living, working, and studying in the U.S. under the Trump administration.

OpenAI didn’t immediately respond to a request for comment. However, in a post on X in July 2023, CEO Sam Altman called for changes to make it easier for “high-skill” immigrants to move to and work in the U.S.

In a statement emailed after this story was published, an OpenAI spokesperson said: “This application was filed some time prior to our employee joining OpenAI and we were not involved in the case. However, our initial assessment, based on the information provided to us, shows there may have been some paperwork issues in the filing. We’re continuing to work closely with our employee on their situation.”

Over the past few months, more than 1,700 international students in the U.S., including AI researchers who’ve lived in the country for a number of years, have had their visa statuses challenged as part of an aggressive crackdown. While the government has accused some of these students of supporting Palestinian militant groups or engaging in “antisemitic” activities, others have been targeted for minor legal infractions, like speeding tickets or other traffic violations.

On Friday, the administration abruptly walked back its cancellation of student visas. But the reprieve may be only temporary. The government says it’s working on a “new system” for reviewing and terminating visas for international students.

Meanwhile, the Trump administration has turned a skeptical eye toward many green card applicants, reportedly suspending processing of requests for legal permanent residency submitted by immigrants granted refugee or asylum status. It has also taken a hardline approach to green card holders it perceives as “national security” threats, detaining and threatening several with deportation.

AI labs like OpenAI rely heavily on foreign research talent. According to Shaun Ralston, an independent contractor providing support for OpenAI’s API customers, OpenAI filed more than 80 applications for H-1B visas last year alone and has sponsored well over 100 visas since 2022.

The U.S. just denied immigration to one of the principal researchers behind OpenAI’s GPT-4.5. 🤦🏽‍♂️ @DavidSacks https://t.co/rXd3vaZj2P

— Ali Partovi (@apartovi) April 25, 2025

H-1B visas, favored by the tech industry, allow U.S. companies to temporarily employ foreign workers in “specialty occupations” that require at least a bachelor’s degree or the equivalent. Recently, immigration officials have begun issuing “requests for evidence” for H-1Bs and other employment-based immigration petitions, asking for home addresses and biometrics, a change some experts worry may lead to an uptick in denied applications.

Immigrants have played a major role in contributing to the growth of the U.S. AI industry.

According to a study from Georgetown’s Center for Security and Emerging Technology, 66% of the 50 “most promising” U.S.-based AI startups on Forbes’ 2019 “AI 50” list had an immigrant founder. A 2023 analysis by the National Foundation for American Policy found that 70% of full-time graduate students in fields related to AI are international students.

Ashish Vaswani, who moved to the U.S. to study computer science in the early 2000s, is one of the co-creators of the transformer, the seminal AI model architecture that underpins chatbots like ChatGPT. One of the co-founders of OpenAI, Wojciech Zaremba, earned his doctorate in AI from NYU on a student visa.

The U.S.’s immigration policies, cutbacks in grant funding, and hostility to certain sciences have many researchers contemplating moving out of the country. Responding to a Nature poll of over 1,600 scientists, 75% said that they were considering leaving for jobs abroad.

Updated 5:08 p.m. Pacific: Added a statement from an OpenAI spokesperson.