At older adulthood, people may experience changes with memory recall and the use of language. They may exhibit behaviors of concern such as agitation and aggression more than is customary. Some may have altered reasoning, judgment, and decision-making abilities that can be cause for concern for family members and carers. Cognitive decline at older age is associated with an increased risk of various adverse health and functional outcomes, including the loss of the ability to perform everyday life activities. This chapter considers the subtle deterioration of an older adult’s cognitive abilities that are beyond the “normal” aging process and is commonly referred to as Mild Cognitive Impairment (MCI). First, the chapter defines MCI in relation to other forms of cognitive impairment that are less severe nature such as subjective cognitive decline (SCD), in addition to those of a more severe nature, such as Alzheimer’s disease. Furthermore, it considers the socio-cognitive and biomedical theories of MCI, leading to an outline of the history of MCI over the past three decades. Second, the chapter discusses how MCI may show in as difficulties of older adults carrying our activities of living and participation in life roles to be more than others of the same age. The chapter also considers how the older adults’ environmental and personal attributes may influence how they manage their life situations. Third, the chapter briefly discusses a range of health-promotive biomedical and behavioral approaches that can be implemented to improve the well-being, safety, and occupational engagement of older adults with MCI. Finally, the chapter proposes collaborative ways for improving the health and functioning of older adults with MCI, of which accurate diagnosis would be an important first step to ensuring older adults get the supports they need.