Research in MCI increased rapidly, showing that this was an intermediate status between normal cognition and dementia that could potentially open the door to early detection of dementing disorders, so MCI received an ICD-9 code. The ICD-9 code for MCI is 331.83 (ICD List, 2020) and F06.7 in ICD-10 (World Health Organization, 2016). Cognitive assessment of MCI is still not fully standardized, with different groups using different tools both in research and clinical settings. MCI remains underdiagnosed, especially among older adults. As MCI is part of the dementia continuum many recommendations for the diagnosis of MCI have been included in dementia clinical practice guidelines. Learn more in this Lecture.