A power management system includes a facility including an adjustment power supply to which feed-in tariff is applied. The power management system includes an equipment management apparatus that manages the adjustment power supply, and a power management server that manages a reverse power flow output from the facility to a power grid. The equipment management apparatus includes a transmitter transmitting, to the power management server, a message including an information element with which an expiration timing of a period to which the feed-in tariff is applied is allowed to be specified.