ImportanceEstablishing a formal definition for neurological device abandonment has the potential to reduce or to prevent the occurrence of this abandonment.ObjectiveTo perform a systematic review of the literature and develop an expert consensus definition for neurological device abandonment.Evidence ReviewAfter a Royal Society Summit on Neural Interfaces (September 13-14, 2023), a systematic English language review using PubMed was undertaken to investigate extant definitions of neurological device abandonment. Articles were reviewed for relevance to neurological device abandonment in the setting of deep brain, vagal nerve, and spinal cord stimulation. This review was followed by the convening of an expert consensus group of physicians, scientists, ethicists, and stakeholders. The group summarized findings, added subject matter experience, and applied relevant ethics concepts to propose a current operational definition of neurological device abandonment. Data collection, study, and consensus development were done between September 13, 2023, and February 1, 2024.FindingsThe PubMed search revealed 734 total articles, and after review, 7 articles were found to address neurological device abandonment. The expert consensus group addressed findings as germane to neurological device abandonment and added personal experience and additional relevant peer-reviewed articles, addressed stakeholders’ respective responsibilities, and operationally defined abandonment in the context of implantable neurotechnological devices. The group further addressed whether clinical trial failure or shelving of devices would constitute or be associated with abandonment as defined. Referential to these domains and dimensions, the group proposed a standardized definition for abandonment of active implantable neurotechnological devices.Conclusions and RelevanceThis study’s consensus statement suggests that the definition for neurological device abandonment should entail failure to provide fundamental aspects of patient consent; fulfill reasonable responsibility for medical, technical, or financial support prior to the end of the device’s labeled lifetime; and address any or all immediate needs that may result in safety concerns or device ineffectiveness and that the definition of abandonment associated with the failure of a research trial should be contingent on specific circumstances.