Cognitive decline is a common consequence of aging and neuropsychiatric conditions that can lead to dementia and impairment in everyday functional activities, which may in turn prompt institutional placement and loss of independence. Veterans are at increased risk of cognitive decline, and the VA is now providing health care to surging numbers of older Veterans who report significant cognitive complaints, difficulties with everyday functioning, and concerns about impending dementia. Treatments to reverse or reduce the consequences of decline are urgently needed. Our study team has previously developed and validated protocols for Compensatory Cognitive Training (CCT) interventions that train cognitive strategies and habits relevant to attention, learning/memory, and executive functioning to improve everyday functioning in the real world. Despite clear, immediate, CCT-based gains in cognitive and everyday functioning in Veterans with multiple causes of cognitive impairment, questions remain about the long-term durability of CCT. Additionally, while systematic reviews and meta-analyses indicate that booster intervention sessions can help maintain treatment gains, these have not yet been developed for CCT. The proposed CDA provides a golden opportunity to evaluate both the long-term durability of CCT and to develop and pilot test the effects of booster treatment. Specific aims are 1) to evaluate the durability of CCT at 24 months in the areas of cognitive performance, performance-based functional capacity, subjective functioning, and quality of life, 2) to develop a series of CCT booster intervention modules focused on aspects of cognition and everyday function, and 3) to conduct a pilot randomized controlled trial (RCT) of the CCT booster intervention to establish feasibility and acceptability. We will recruit Veterans aged 55 or older who previously participated in a VA Merit study of CCT for older Veterans with Mild Cognitive Impairment [CSRD: I01CX001592; PI: Twamley]. The candidate, Dr. Jacqueline Maye, is currently a Postdoctoral Fellow at the VA San Diego Healthcare System. Her long-term career goal is to be an independent, VA-funded investigator focused on improving cognitive health and function for older Veterans. Training objectives center on cognitive rehabilitation concepts and research practices, RCTs for older Veterans with cognitive impairments, advanced longitudinal techniques, and professional development. The proposed study complements these goals, with a mentorship team that includes experts in aging, cognitive rehabilitation, intervention and RCT design, and advanced statistical methodology. Project findings will be critical to the candidate’s mission to advance cognitive rehabilitation science and deliver long-term, sustained benefits to Veterans through CCT. Results will inform post-CDA research goals to implement boosters widely with future CCT participants.