I cannot create a summary of the requested article because the search results provided do not include an article titled "STAT+: AI Prognosis: Who's keeping tabs on how health insurers are using AI?" nor its content. The search results include information on Slovakian health insurance for 2026, health care priorities and insurance companies' economic results, but not the article on the use of AI by health insurance companies by Casey Ross of STAT. In order to create an accurate and factual summary, I would need access to the article itself or its full text.