May 27, 2025
Ambience announces OpenAI-powered medical coding model that outperforms physicians
Ambience is part of the red-hot market that uses AI to draft clinical notes in real time as doctors consensually record their visits with patients

Dr. Priti Patel, CMIO at John Muir Health, uses Ambience before starting a patient encounter.

Courtesy of Ambience Healthcare

Artificial intelligence startup Ambience Healthcare on Tuesday announced a new medical coding model that outperforms doctors by 27%.

Ambience uses AI to draft clinical notes in real-time as doctors consensually record their visits with patients. The company used tools from OpenAI to build the new model.

The startup is part of a fiercely competitive market that has taken off as health-care executives search for solutions to help reduce staff burnout and daunting administrative workloads. 

The company’s new model can listen to patient encounters and identify ICD-10 codes, which are internationally standardized classifications for different diseases and conditions. There are about 70,000 ICD-10 codes that are regularly updated and used to facilitate billing and other reporting processes in health care. 

Ambience said its new ICD-10 model can reduce billing mistakes and help clinicians and professional coders work more efficiently. The model notched a “27% relative improvement over physician benchmarks,” according to a release on Tuesday.  

“We’re not replacing doctors or coders,” Brendan Fortuner, Ambience’s head of engineering, told CNBC in an interview. “What we’re doing is we’re liberating them from administration, and we’re fixing mistakes that help make health care better, safer, more cost-effective.”

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Documenting ICD-10 codes has traditionally been a labor-intensive task in health care, but it’s a crucial way to track outcomes, mortalities and morbidities in a standardized way, said Dr. Will Morris, the chief medical officer of Ambience.

“If you think about it from a data perspective, it’s how you can compare and contrast clinician A to B, or health system A to B,” Morris said in an interview. “It’s the cornerstone for quality.”

Ambience’s technology is used at more than 40 health-care organizations, like Cleveland Clinic and UCSF Health. It has raised more than $100 million, according to PitchBook, from investors including Kleiner Perkins, Andreessen Horowitz and the OpenAI Startup Fund. 

The company is reportedly seeking fresh capital at a valuation of over $1 billion, according to a report from The Information. Ambience declined to comment on the report. 

Ambience trained its new AI model using OpenAI’s reinforcement fine-tuning technology. This technology allows companies to tune OpenAI’s best reasoning models for very specific domains, like health care. 

To validate the model, Ambience tested it against a “gold panel” set of labels, the company said. The labels were established by a group of expert clinicians who evaluated complex clinical cases and came to an agreement on what the right codes were. 

Ambience’s AI platform for compliant documentation, CDI, and coding.

Courtesy of Ambience Healthcare

The company then recruited 18 different board-certified doctors and compared their performance on ICD-10 coding accuracy to the model’s performance. That comparison showed the Ambience technology performed 27% better than the physician baseline. 

“It shows for the first time that an AI system can actually surpass clinician experts at a very, very important administrative task, especially in coding,” Fortuner said. 

Ambience already has similar capabilities available for other medical codes like Current Procedural Terminology (CPT) codes, and Fortuner said it’s exploring how to tackle other areas like prior authorizations, utilization management and clinical trial matching. 

The company’s new ICD-10 model will roll out to customers over the summer.

“Getting it right at the point of care is a fundamental change,” Morris said.