We revised our U.S. health insurance sector view to negative from stable because of the recent and projected strain in operating performance, predominantly in the Medicare Advantage and Medicaid segments, and in certain geographic markets; a rising share of negative rating outlooks based on company-specific earnings deterioration and criteria changes; and higher legislative and regulatory risk, which could affect both health insurance and pharmacy-related segments. Nevertheless, long-term sector fundamentals remain solid due to the average financial strength rating of 'A/A-' among the rated companies reflects strong and stable competitive positions, supported by overall pricing flexibility, favorable long-term growth prospects, and high barriers to entry; and sound balance sheets, manageable leverage, and healthy operating cash flows also provide financial flexibility that supports overall credit quality