A study by the Blue Cross Blue Shield Association released on September 24 found that AI-assisted medical coding added nearly $1 billion in extra costs for its member insurers over two years, compared with 2023 levels.

Between 2024 and 2025, providers more frequently billed for secondary or coexisting conditions, driving $653 million in added costs for BCBS companies, according to Reuters. More intensive documentation overall added $942 million over two years versus 2023.

The study says providers used AI to scan patient records for missed conditions and ambient clinical scribes that listen to doctor-patient conversations and draft notes. BCBSA covers 31 insurers and more than 100 million people; the study analyzed inpatient billing.

For major bowel surgeries, secondary conditions like partial intestinal blockages and acid overload rose 55% and 33% respectively between the first quarter of 2023 and the fourth quarter of 2025, while treatment rates stayed largely unchanged. “If patients are truly sicker, we’d expect to see more treatment,” said Luke Chalker, BCBSA’s senior vice president of product and data science. BCBSA said the increase does not necessarily indicate inappropriate AI use. No hospital industry response was retrieved in the coverage reviewed.