Recent breakthroughs in Alzheimer disease (AD) therapeutics show promise, particularly in early-stage disease. Yet, identifying individuals in these early stages is challenging. Relying solely on cognitive markers to detect preclinical AD is limited, since cognition at this stage is normal by definition. Research is shifting toward noncognitive markers of disease, such as late-onset neuropsychiatric symptoms (NPS), which are common in dementia but can also emerge before dementia diagnosis. Mild Behavioral Impairment (MBI) is a framework for identifying high-risk individuals for incident dementia based on later-life persistent new-onset NPS. The inclusion of MBI in the National Institute on Aging-Alzheimer’s Association (NIA-AA) Clinical Staging Framework underscores its importance in early disease detection, necessitating further research into reliability, predictive value, and associations with AD pathology. Longitudinal studies consistently demonstrate MBI associations with incident cognitive decline and dementia, outperforming traditional NPS models. Neuroimaging findings link MBI with early AD-related changes in brain structure, function, and pathology. Biomarker studies show MBI associations with elevated amyloid-beta Amyloid beta (Aβ)and tau deposition, supporting MBI as an early clinical manifestation of AD. Leveraging MBI in conjunction with cognitive status could offer an accessible and effective strategy for identifying individuals with early-stage AD, enhancing recruitment strategies for AD clinical trials, and potentially accelerating development of disease-modifying therapies to improve patient and caregiver outcomes.