Elevance Health surprised Wall Street with a rare, late-year guidance cut Thursday after a jump in Medicaid costs marred its third quarter.Shares of the Blue Cross-Blue Shield insurer tumbled after it joined rival UnitedHealth in noting that rates it receives for managing government-funded Medicaid programs weren't enough to offset a rise in costs.

We remain confident in the long-term earnings potential of our diverse businesses as we navigate a dynamic operating environment and unprecedented challenges in the Medicaid business,” Chief Executive Gail K.