Walgreens said Sunday it is is terminating its relationship with Theranos and closing the operations at all 40 Theranos Wellness Centers at its Arizona stores.

The action decision comes after Walgreens' decision in January to halt Theranos laboratory testing services at its Palo Alto location. At that time, Walgreens informed Theranos to stop sending clinical laboratory tests provided through its Walgreens wellness centers to the Theranos lab in Newark, California, which has been under review by the Centers for Medicare and Medicaid Services. Walgreens had asked that tests only be sent to Theranos' certified Phoenix-area lab or to an accredited third-party lab for analysis until the Newark lab issue was resolved.

Walgreens will no longer offer Theranos services at any of its Arizona stores and will work to help customers find new options.

“In light of the voiding of a number of test results, and as the Centers for Medicare and Medicaid Services has rejected Theranos’ plan of correction and considers sanctions, we have carefully considered our relationship with Theranos and believe it is in our customers’ best interests to terminate our partnership,” Brad Fluegel, Walgreens senior vice president and chief health care commercial market development officer, said.