Shares of Elevance tumbled early Thursday after the insurer said rising Medicaid costs prompted a 2024 forecast cut less than three months before the year's end.

The Blue Cross-Blue Shield insurer said it was dealing with a "timing mismatch" between Medicaid rates and higher claims from its customers. The company dropped its forecast for 2024 adjusted earnings to approximately $33 per share after predicting at least $37.20 in July.

Wall Street expects $37.25 per share, according to the data firm FactSet.

Insurers typically act conservatively with their forecasts this late in the year and focus on signaling to investors how the coming year will play out.

With more than 8.9 million people enrolled, Elevance is one of the country's biggest insurers in Medicaid, the state- and federally funded program that pays for health care for people with low incomes. States hire insurers to manage their Medicaid programs.

Elevance said Thursday its Medicaid enrollment tumbled 19% from 11 million people in last year's third quarter. States have been going through a process to redetermine Medicaid eligibility after enrollment in the program swelled during the COVID-19 pandemic.

Elevance said that process led to an unfavorable mix shift in its Medicaid membership, which hurt the operating gain for its health benefits business.

Insurers have been wary of redetermination because of concerns that the process would remove healthy people from their enrollment and leave a higher concentration of people who use the coverage and generate claims.

Overall, the Indianapolis-based company's profit slipped 21% in the recently completed third quarter to $1.02 billion. Operating revenue, which excludes investment gains, rose 5% to $44.72 billion.

Adjusted earnings totaled $8.37 per share.

Analysts expected $9.66 per share on $43.47 billion in revenue.

Shares of Elevance Inc. tumbled nearly 12% to $438 before markets opened Thursday.