CVS Health Corp. is losing Walmart as a pharmacy partner in two networks.

CVS said that Walmart has opted to leave the CVS Caremark pharmacy benefit management commercial and managed Medicaid retail pharmacy networks. CVS Caremark has asked Walmart to fill these prescriptions as in-network through April 30.

The change will not affect Walmart’s participation in CVS Caremark’s Medicare Part D pharmacy network. Also, Walmart’s Sam’s Club will stay in the networks that Walmart is leaving.

The point of contention, according to CVS Health, is reimbursement rates.

“At a time when everyone is working hard to find ways to reduce health care costs, Walmart’s requested rates would ultimately result in higher costs for our clients and consumers,” CVS Caremark president Derica Rice, said. “While we…