Abstract: Neural interfaces can be implanted throughout the body to restore function, including cochlear implants for severe hearing loss, deep brain stimulation for tremor, and spinal cord stimulation for pain. These devices are intended to remain implanted and effective for the lifetime of the user, which could be several decades. Device performance and longevity can be impacted by the state of the electrode-tissue interface. Electrochemical performance and tissue reaction to implanted electrodes are important factors to consider when testing novel electrodes and materials, and can facilitate understanding of the reactions at the interface. The works summarized in this perspective highlight the significance of evaluating the electrochemical properties and bioreactivity of implanted electrodes in concert through chronic in vivo studies. Cochlear implants are used as a case study; however, the results are relevant to all neural interfaces. Electrochemical performance and tissue reactivity must be considered in future studies evaluating electrodes and materials prior to testing in people.