An ambulatory medical device includes a sensor configured to acquire a signal indicative of a physiological condition of a patient, a controller operatively coupled to the sensor and configured to monitor the physiological signal, and to perform a diagnostic test, and a remote access manager operatively coupled to the controller and configured to monitor for a command from a remote system to perform the diagnostic test, and to cause the controller to perform the diagnostic test in response to the command. In the device, the remote access manager may be further configured to transmit data representing an operational status of the ambulatory medical device to the remote system. The operational status of the controller may result from performing the diagnostic test. The remote access manager may be further configured to send the data representing the operational status of the ambulatory medical device in real time or substantially in real time.