Why CVS Health Stock Is Tumbling Thursday

CVS Health Corp CVS shares are trading lower Thursday following reports that Blue Shield of California plans to drop CVS's Caremark as its pharmacy benefit manager.

What To Know: Blue Shield will drop CVS and begin working with Amazon.com Inc AMZN and billionaire entrepreneur Mark Cuban's Cost Plus Drug Company, according to a Wall Street Journal report.

Pharmacy benefit managers help negotiate prescription drug prices between drug manufacturers and pharmacies and manage benefits on behalf of insurers. 

The news comes after Centene Corp CNC replaced CVS as its pharmacy benefit manager late last year in a move aimed at cutting costs. CVS shares faced selling pressure at the time. The stock is under pressure again Thursday morning.

See Also: Amazon's Boon for Diabetes Patients, Streamlining Pharmacy Discounts

CVS Price Action: At publication time, CVS shares were down 7.18% at $67.50, according to Benzinga Pro.

Photo: Mike Mozart from Flickr.