Background: GA evaluates aging-related domains (e.g., function) known to be associated with cancer treatment toxicity. We found that providing a GA summary with management recommendations to oncologists reduces clinician-rated toxicity in older patients (pts) with advanced cancer receiving high risk treatment (presented @ASCO2020). Herein, we report secondary outcomes on the effects of the GA intervention on aging-related outcomes. Methods: Pts aged ≥ 70 with incurable solid tumors or lymphoma and ≥ 1 impaired GA domain starting a new treatment regimen were enrolled. Community oncology practices were randomized to intervention (oncologists received GA summary/recommendations) or usual care (none given). Secondary analyses examined effects of the intervention on functional outcomes (patient-reported falls, instrumental activities of daily living (IADL), short physical performance battery (SPPB), geriatric depression scale (GDS), and medications [total and prescription]). Outcomes were analyzed using linear mixed effects model, logistic or Poisson regression adjusted for baseline values, time, and site effects as appropriate. Results: From 2013-19, 718 pts were enrolled from 41 practices. Age (mean 77 yrs), sex (43% women), number of impaired GA domains (median 4/8), and treatment type (chemotherapy 88%) were not different by arm. More pts in intervention were black (12% vs 3%, p<0.01), had GI cancer (38% vs 31%, p<0.01), and had prior chemotherapy (31% vs 23%, p=0.02). Overall, 16.4% of all pts had one new fall over 3 months; patients in the intervention arm were significantly less like to fall over 3 months (11.7% vs 20.7%; Risk Ratio 0.58; 95% CI 0.40-0.84, p=0.004). There was no difference in the total number of medications (mean 5.86 vs 5.79, p=0.80) and prescriptions (mean 4.26 vs 4.20, p=0.70) at baseline. More medications (adjusted mean 0.23 vs 0.09, p=0.03) and prescriptions (0.19 vs 0.07, p=0.05) were discontinued during intervention, although there was no difference at 3 month follow up. There were no significant between-arms differences in IADL, SPPB, and GDS. Conclusions: Providing GA information to oncologists reduces the proportion of older pts who experience a fall over 3 months and improves polypharmacy; both of these endpoints are of clinical importance to older adults with aging-related conditions and advanced cancer undergoing palliative treatment. Funding: R01CA177592, U01CA233167, UG1CA189961. Clinical trial information: NCT02054741.