Systems and methods for tracking prescription drug inventory of a pharmacy at a switch. Embodiments of the invention include receiving, at a switch, a prescription claim transaction from a pharmacy system, where the prescription claim transaction indicates an amount of a drug, and transmitting the prescription claim transaction to a payer system for adjudication. An adjudicated response for the prescription claim is then received from the payer system, and an inventory amount associated with the drug maintained by the switch is updated by the switch. When a determination is made that the inventory amount has met a threshold value, a message is transmitting indicating that the inventory amount has met the threshold value. In some embodiments of the invention the message is sent to the pharmacy or directly to a supplier as part of an order for additional inventory of the drug.