Techniques for retrieving information from an implantable medical device (IMD) having a depleted internal energy source such as a non-rechargeable battery are disclosed. The IMD is powered by and communicates with an external interrogation device to access a memory location of the IMD and for transfer of the information in the memory location to the external interrogation device subsequent to depletion of the internal energy source. In an embodiment, the memory location is included in a non-volatile memory component of the IMD to maintain the information stored in the memory component.