==== Front Innov Aging Innov Aging innovateage Innovation in Aging 2399-5300 Oxford University Press US 10.1093/geroni/igaa057.2453 igaa057.2453 Abstracts Session 6160 (Symposium) AcademicSubjects/SOC02600 Lessons Learned in a Community-Based, Randomized Controlled Trial of a Complicated Grief Intervention Buck Harleah 1 Cairns Paula 1 Emechebe Nnadozie 1 Hernandez Diego 1 Mason Tina 1 Bell Jesse 2 Kip Kevin 1 Tofthagen Cindy 3 1 University of South Florida, Tampa, Florida, United States 2 University of south florida, Tampa, Florida, United States 3 Mayo Clinic, Jacksonville, Florida, United States 2020 16 12 2020 16 12 2020 4 Suppl 1 Program Abstracts from The GSA 2020 Annual Scientific Meeting “Turning 75: Why Age Matters”699 699 © The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America.2020This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Abstract Complicated grief (CG), severe, prolonged (>12 months) grieving, disproportionately affects older adults. A prospective two-group, waitlisted RCT examined whether four sessions of Accelerated Resolution Therapy (ART) was effective in informal caregivers by comparing pre-to-post ART changes and investigating variation in treatment response by baseline CG levels. Inclusion: ≥60 years, Inventory of Complicated Grief >25. Paired t-tests of mean (SD) differences compared pre- to post-ART; pre-ART to 8-week follow-up, and post-ART to 8-week follow-up; then stratified by median baseline level of CG. Mean (SD) age of 54 participants was 68.7 (7.2) years, 85% female, and 93% white. Significantly greater CG reduction (-22.8 (10.3)) vs. waitlist (-4.3 (6.0)) was found. Within-participant effect sizes from baseline to 8-weeks post treatment were 1.96 (95% CI: 1.45, 2.47; p<0.0001). Treatment effects did not substantially differ by baseline levels. Lesson learned was that it was possible to successfully recruit and treat CG in the community.