Abstract The overall goal of this project is to collect pilot feasibility and early efficacy data showing improvements in cognition and wellbeing in adults with mild cognitive impairment (MCI) through a combination treatment of non-invasive brain stimulation (transcranial alternating current stimulation (tACS)) and a novel form of closed-loop digital meditation (Meditrain). MCI is a transitional stage between normal aging and dementia, and patients with MCI are at high risk of progressing onto Alzheimer’s disease and other dementias. Non-invasive brain stimulation and focused-attention meditation are two approaches that hold great promise for boosting cognitive abilities and enhancing wellbeing in OA at risk of Alzheimer’s disease. While a handful of studies have combined neural stimulation with meditation in healthy young adults, none have employed digital closed loop meditation nor examined this question in a population at high risk of Alzheimer’s disease. Thus, the goal of this proposed research is to collect pilot data to test the hypothesis that coupling MediTrain with frequency-specific (i.e., theta) tACS targeting frontal attention networks will lead to faster and/or greater magnitude of gains in cognitive abilities, real-world indices of stress and sleep, and key blood biomarkers of aging in aMCI patients. To accomplish these aims, we will conduction an RCT on 90 OA with aMCI who will be assigned to one of three intervention groups: MediTrain + 6Hz tACS (n = 30), MediTrain + sham tACS (n = 30), or a placebo (Worder app + sham tACS) intervention (n = 30). Theta (6Hz) or sham (i.e., none) stimulation will be applied to the forehead using Humm patches during 30min of training in participants’ homes, 4 days per week, for 4 weeks. Outcome measures will consist of cognitive/attention tasks, physiological indices of sleep and stress (both in lab and at home via wearable sensors), and blood biomarkers of aging (telomere length). This research will provide an important contribution toward understanding the combination of tACS and meditation as a therapeutic tool for bolstering cognitive reserve and increasing overall wellbeing in patients with MCI.