["British Journal of Learning Disabilities, EarlyView. ", "\nABSTRACT\n\nBackground\nAdults with intellectual disabilities, particularly those with Down's syndrome, are at increased risk of developing dementia, yet early changes are often subtle and first noticed by family members or paid support staff rather than clinicians. While validated diagnostic instruments exist, they are designed for specialist assessment and serve a different purpose from routine caregiver observation and documentation.\n\n\nMethods\nUsing an iterative co‐design approach, we combined an updated review of existing instruments, secondary analysis of lived‐experience data, discussion groups, consensus workshops, and qualitative usability feedback involving people with intellectual disabilities, family carers, paid support staff and clinicians.\n\n\nFindings\nCo‐design identified priority domains reflecting functional, behavioural, emotional and communication changes that may precede diagnosis, particularly among people with Down's syndrome. A 14‐item informant‐based checklist and tracking framework were developed. Face and content validity were supported through stakeholder review. Users estimated completion time at 10–15 min and reported good acceptability and usability.\n\n\nConclusion\nEarlyMind‐ID represents a co‐designed, early‐stage checklist and tracking framework intended to support caregiver observation alongside existing diagnostic assessment processes. Further work is required to examine feasibility, implementation and measurement properties before any clinical application.\n"]