The company, which runs a large mail-order facility in Las Vegas, could lay off the technicians as soon as Saturday over conflicts about healthcare benefits, the Wall Street Journal said Monday. Employees facing lockout are primarily people who check labels and otherwise prepare pills for shipment.

Medco wants to increase their cost-sharing of healthcare benefits to bring them in line with other Medco employees, a company spokeswoman said.

Pharmacists are not involved in the dispute.