**Washington:** ChatGPT captured nearly 90% of all identifiable artificial intelligence (AI) spending by U.S. House offices, committees, and institutional accounts over the 12 months ending March 31, according to an analysis of House disbursement records by CNBC.
The report found that House offices made at least **$113,740** in traceable payments to AI vendors during the period. Of that amount, **ChatGPT received $100,580 across 798 transactions**, representing approximately **88% of total AI spending** and **96% of all identified AI-related transactions**.
Anthropic's **Claude** ranked second, with **$13,160 spread across 37 transactions**.
The analysis reflects only a portion of Congress' AI usage. It excludes free AI accounts, AI features bundled into enterprise software such as Microsoft Copilot, and most Senate-related spending because House records do not clearly identify vendors for Senate purchases.
### Democratic Offices Spent More on AI
The data also showed a notable difference in spending between political parties.
Democratic House offices accounted for **$54,165** in identifiable AI purchases, more than three times the **$15,782** spent by Republican offices. ChatGPT subscriptions appeared in **44 Democratic offices** and **27 Republican offices**.
### AI Becoming a Daily Tool for Congressional Staff
According to **Marci Harris**, CEO of the POPVOX Foundation, congressional staff are increasingly relying on AI for everyday work, including summarizing legislation, drafting internal memos, preparing for committee hearings, and responding to constituent inquiries.
Harris noted that staff workloads continue to grow as lobbyists and constituents also use AI to produce longer and more detailed communications, increasing the volume of information congressional offices must process.
### AI Saving Staff Time
Representative **Julie Fedorchak** (R-N.D.) said her office uses ChatGPT to create a searchable database of legislation and constituent information. The AI system then generates briefing memos based on that data.
According to Fedorchak, the process is saving staff "dozens and dozens of hours every week," allowing employees to focus on higher-priority legislative work.
### Early Adoption Helped ChatGPT Gain Ground
ChatGPT's strong presence on Capitol Hill is linked to its early rollout within Congress.
In 2023, the House Digital Service distributed the first 40 ChatGPT Plus licenses to a bipartisan group of congressional staff. OpenAI also partnered with the Congressional Management Foundation to conduct training sessions for senior House and Senate employees.
### AI Companies Increasing Washington Lobbying
As AI adoption grows across government, lobbying efforts by leading AI companies have also accelerated.
Federal lobbying disclosures reviewed by Issue One show that OpenAI spent **$1 million on lobbying during the first quarter of 2026**, an increase of **82.5%** compared with the same period in 2025.
Anthropic reported nearly **$1.6 million in first-quarter 2026 lobbying expenditures**, more than tripling its spending from a year earlier.
### Experts Call for Broader AI Evaluation
**Eric Petry** of the Brennan Center for Justice said lawmakers and congressional staff should gain practical experience with multiple AI platforms before developing regulations for the rapidly evolving technology.
He said evaluating a variety of AI systems would help ensure taxpayer money is spent on the most effective tools rather than favoring any particular company.