Artificial intelligence tools used by hospitals to review patient records and prepare clinical documentation are intensifying disputes between providers and insurers over medical billing. A Blue Cross Blue Shield Association report said hospitals’ AI-assisted coding was associated with nearly $1 billion in additional expenses over two years. Hospitals submitted claims describing tens of thousands of patients as having more complex illnesses in 2024 and 2025 than in 2023, although the analysis found no evidence that those patients received different treatment. Adding secondary diagnoses such as anemia or low sodium increased payments by an average of nearly $12,000 per case. The findings build on earlier BCBSA analyses that attributed $942 million in additional inpatient costs and an estimated $2.3 billion in nationwide inpatient and outpatient costs to AI-linked coding trends.