Congress has a favorite AI, and it isn't close.
CNBC's review of public spending records from the U.S. House of Representatives found that identifiable AI tool purchases totaled at least $113,700 in the year ending March 31, 2026. OpenAI's ChatGPT grabbed $100,600 of that across 798 transactions — roughly 88% of the total. Anthropic's Claude finished second with just $13,200 across 37 purchases.
ChatGPT showed up in at least 71 congressional offices, or about one-sixth of the House. Staffers use it to summarize legislation, write memos, prepare for hearings, answer constituent mail, and draft social media posts.
The numbers don't include free accounts, AI features baked into existing software subscriptions, or most Senate spending. But among the standalone AI tools that left a traceable paper trail, ChatGPT is lapping the field.