A Walmart-CVS pharmacy dispute is likely going to cause problems for customers.

The dispute was announced on Tuesday with CVS (NYSE:CVS) saying that Walmart (NYSE:WMT) is leaving its “pharmacy benefit management (PBM) commercial and Managed Medicaid retail pharmacy networks.”

The Walmart-CVS pharmacy dispute has to do with pricing. CVS claims that Walmart was seeking reimbursement increases that it claims would result in  higher costs for both clients and consumers. CVS refused this request, which is the reason behind the split.

“While we have enjoyed a long relationship with Walmart as a low cost provider in our broad national networks, based on our commitment to helping our clients and consumers manage rising pharmacy costs, we simply could not agree to their recent demands for an increase in reimbursement,” Derica Rice, President of CVS Caremark, said in a statement.

So how exactly will the Walmart-CVS pharmacy dispute affect customers. It may make it harder for some customers to get their prescriptions filled. However, CVS is working with Walmart to have it act as an in network participating pharmacy through April 30, 2019.

While the Walmart-CVS pharmacy dispute is sure to cause problems for some customers, CVS argues it won’t be as bad as it seems. It claims that less than 5% of its members user Walmart pharmacies exclusively. It also says that customers still have plenty of options for filling their prescriptions that are within the same travel distance as WMT locations.

CVS stock was down 1% and WMT stock was up 1% as of Tuesday afternoon.

As of this writing, William White did not hold a position in any of the aforementioned securities.