In a dispute over reimbursements, Walmart has stated that it will leave the prescription network administered by the pharmacy-benefits division of CVS Health. Publicly, there’s finger pointing on both sides, but at its most basic, CVS seems unwilling to pay the level of reimbursements Walmart seeks for prescription drugs sold through its 4,700 pharmacies. Whether Walmart has asked for an increase in payments or CVS Caremark has sought to reduce payments is an open question.

This story plays out within the larger context of CVS’s acquisition of insurer Aetna last year and Walmart’s seeming desire to become a larger player in the healthcare space, as we noted last summer with its hire of Sean Slovenski, formerly of Humana, as Senior VP of Health and Wellness.

The split could occur as early as February, but CVS Caremark has requested that Walmart stick around until April, leaving room for the two parties to come to a resolution. Should Walmart leave the network, individuals with employer plans that utilize CVS Caremark to administer benefits or Medicaid-based CVS drug coverage would no longer be covered. Sam’s Club pharmacies would not be affected by such a move.