T he U.S. government entrusts classified material to individuals who possess a security clearance (Department of Defense Manual [DoDM] 5200.01, 2013). But how do these trusted individuals remain good custodians of that classified information if they are impaired? Two trends might contribute to a new type of national security threat: (1) People are living longer, and (2) people are working later in life. As a result, the workforce might experience a higher prevalence of dementia than in past generations. Taken together, we believe that an increasing number of cleared personnel-that is, personnel who hold or have held security clearances-have or will have dementia.Dementia is often an unfortunate consequence of abnormal aging. Increasing age is the greatest risk factor for developing dementia (Alzheimer's Association, undated-a). The U.S. population of adults ages 65 and older will double between 2000 and 2040 (U.S. Department of Health and Human Services, Administration for Community Living, 2018). In turn, an increase in the number of individuals with Alzheimer's disease and related dementias is expected to accompany this