In general, this disclosure is related to detecting overload within an analog-to-digital converter (ADC) of an implantable medical device (IMD). The IMD may include an overload detection module that determines whether the ADC is operating in an overload condition. When the overload detection module determines the ADC is operating in the overload condition for a particular period of time, the ADC may send an overload signal to a processor that processes the output of the ADC. The overload signal notifies the processor that the ADC is operating in or is close to operating in the overload condition. In response to the indication from the ADC, the processor of the IMD may disregard the output of the ADC. The processor may continue to disregard the output of the ADC until the overload signal is deactivated, thereby indicating that the ADC is no longer in an overloaded condition.