As the number of Canadians diagnosed with cognitive impairment continues to increase, so will the demands on family members and friends who are providing them with care and support. Mild cognitive impairment (MCI) is one of the most prevalent forms of cognitive impairment, and it is associated with a higher probability of progression to dementia. Thus, investing in support services to sustain MCI care partners is critical. The overarching objective of this dissertation was to gain clarity on MCI care partners’ caregiver identity and mental health to inform support services tailored to help address their needs. In Study 1, I conducted in-depth interviews (n=18) to explore how caregiver identity develops in family and friends of individuals with MCI, and analyzed the data according to constructivist grounded theory. The overarching themes influencing MCI caregiver identity included: MCI changes; care-related experiences; “caregiver” interpretation; and approach/avoidance coping. These themes influenced how participants primarily identified, represented as: “I am a caregiver,” “I am not a caregiver,” or “liminality,” and all conveyed thinking about their “future self” as providing more intensive care. These findings underscore that irrespective of how individuals identified, they were engaging in care, and would likely benefit from support with navigating these changes and their evolving roles. In Study 2, my first objective was to compare MCI care partner and dementia caregiver (n=137) mental health. Results showed that both caregiver groups endorsed notable mental health symptoms, with dementia caregivers endorsing greater anxiety, depression, and burden. To meet my second objective, mediation results indicated that differences between MCI and dementia caregiver mental health were due to (i.e., mediated by) how distressed caregivers were by care-recipient behaviour disruptions and depression symptoms, but not memory symptoms. Results showed that distress regarding care-recipient behaviour disruptions and depression symptoms were equally important mediators in understanding caregiver mental health. These results underscore the importance of preventing or reducing poor mental health for individuals at the MCI stage of caregiving. Overall, findings from this dissertation provide important and additive insights to support MCI care partners along their caregiving trajectories, including implications for health care support services and future research.