An implantable medical device (IMD) configures one or more operating parameters of the IMD based on a type of source of a disruptive energy field to which the IMD is exposed. The disruptive energy field may, in one example, include magnetic and/or radio frequency (RF) fields generated by an MRI scanner. In one aspect, the IMD may distinguish between different types of MRI scanners and select an exposure operating mode tailored to reduce the effects of the particular type of MRI scanner. In another aspect, the IMD may adjust one or more operating parameters that will be used when the IMD returns to a normal operating mode after exposure to the MRI scanner based on the type of MRI scanner to which the IMD is exposed.