Anthropic may have topped OpenAI as the world’s most valuable AI startup a few months ago, but when it comes to power users, Sam Altman’s company still has the edge.
ChatGPT accounted for 88% of all known spending on AI tools by the U.S. House of Representatives between April 1, 2025 and March 31 of this year, according to a study of House disbursement records by CNBC.
The analysis only looks at paid usage, so free accounts are not factored into the equation, nor is any AI usage that’s bundled with larger software contracts. But of the $113,740 spent in named vendors during that period, $100,580 went to ChatGPT. Spending by Democrats was three times that of Republicans, the records show.
Spending on Anthropic’s Claude was a distant second, accounting for $13,160 across just 37 transactions.
The heavy usage by Congressional members and their staff could give OpenAI an edge over its rivals as the debate over AI regulation continues and the government awards contracts to AI giants for a variety of departments.
The totals gathered by CNBC are almost certainly far short of the actual spending by Congress on AI. The data did not include Senate usage (though it’s worth noting the Senate does not allow Claude for official use) and some House offices have individuals sign up for a subscription to an AI service, then reimburse that staffer, which would not be line-itemed in the disbursement records.
Big spending
In some cases, the use of OpenAI could be habitual. ChatGPT was the first major AI chatbot on the market and was the first form of the technology that many members of the House experimented with in 2023, when the legislative body formed an AI working group.
OpenAI and Altman have also been significant donors to many Congressional races and have spent significantly on lobbying in recent years.
In the second quarter of this year, OpenAI spent $1.2 million on lobbying, an increase of nearly 18% from the first quarter and a new record for the firm. It’s also nearly double what it spent in the second quarter last year. (Anthropic, meanwhile, spent $1.97 million from April through June.)
Last year, OpenAI spent nearly $3 million in federal lobbying, and Altman has personally donated more than $126,000 to individual candidates and political parties since the launch of ChatGPT. The vast majority of those donations were to Democrats. Previous donations include six-figure contributions supporting Joe Biden’s 2020 presidential run and $250,000 to the Democratic super PAC American Bridge 21st Century in 2020.
Altman did, however, also personally donate $1 million to Donald Trump’s inauguration fund in 2024. (He’s said he doesn’t plan to make any political donations in the 2026 midterm elections. “I would love to see money out of politics in general,” he said last month.)
Meanwhile, OpenAI co-founder and president Greg Brockman, along with his wife Anna, have committed $50 million to the pro-AI super PAC Leading the Future super PAC, which says it plans to support AI-friendly candidates from both parties during the midterm elections. (Other donors to Leading the Future include private equity giant Andreessen Horowitz and Palantir cofounder Joe Lonsdale.) The Brockmans also gave $25 million to Trump’s MAGA Inc. super PAC in September of 2025.
The heavy House usage of ChatGPT and the political spending of AI companies is increasingly important as momentum grows for government regulation of the industry. Leaders of the top AI companies, including Altman, are expected to gather at the White House Tuesday to discuss a new framework that would allow the government to review frontier AI models before they launch. This comes after models from OpenAI and Anthropic both went rogue and hacked into other companies recently.