Background: Adolescent and young adults (AYAs) with cancer experience chronic stress and poor quality of life, particularly in early posttreatment as AYAs grapple with a “new normal.” Mind-body programs introduced early posttreatment hold promise for providing AYAs with skills to mitigate the adverse psychosocial and physiological effects of stress. Methods: We adapted and piloted an 8-session virtual, mind-body stress management and resilience group program for AYAs (3RP-AYA) to support the posttreatment transition. AYAs were randomized to receive the 3RP-AYA immediately (intervention group; IG) or after 3 months (waitlist control; WC). Data were collected at baseline (T0), 3 (T1) and 6 months (T2). We assessed feasibility by examining 3RP-AYA participation and survey completion rates. Paired-samples t-tests evaluated within-group effects of the 3RP-AYA on coping, distress (worry, depression, uncertainty intolerance), and resilience from T0-T1 (intervention period for IG, waitlist period for WC). Independent-samples t-tests of T0-T1 change scores for each group tested between-group differences in strength of change. Cohen’s d characterized strength of within- and between- group differences. Acceptability (i.e., content satisfaction and perceived helpfulness) was assessed at progam end (T1 for IG, T2 for WC). Results: From 05/19-09/20, 72 AYAs (77% participation rate; Mage = 23.8; 73.6% female; mean 18-months posttreatment; 59.7% non-Hispanic white; 20.8% Hispanic; 25% international) were randomized to IG (n = 35) or WC (n = 37); 85.9% completed 6/8 sessions (median = 7), and 87.5% completed the T1 survey. At enrollment, AYAs presented with elevated worry (M = 52.5, SD = 12.2) and uncertainty intolerance (M = 33.8, SD = 8.7), resembling patients with generalized anxiety. From T0-T1, the IG demonstrated moderate-to-large improvements in coping (d= 0.78, P < .001), worry (d =0.45, p = .04), depression (d= .31, p = .11), tolerance of uncertainty (d = .37, p = .06) and resilience (d =.34, p = .09). When examining between-group differences, the IG showed significantly greater improvement in coping (d = 0.72, p = .01), with non-significantly greater change in worry, depression, tolerance of uncertainty, and resilience (ds = 0.27-0.49, ps > .09) relative to WC. Notably, 96.6% of participants reported overall content satisfaction, and 91.7% reported the 3RP-AYA was helpful. Conclusions: A virtual mind-body program is feasible, acceptable and shows promising efficacy in improving coping and distress among posttreatment AYAs. Findings offer a paradigm shift in the way survivorship care is delivered, suggesting that integrating a mind-body program into early posttreatment survivorship care can facilitate adjustment to life after treatment. This can have downstream effects on the long-term emotional and physical health of AYAs. Clinical trial information: NCT03768336.