e14701 Background: Medical providers often describe concerns about a patient’s functional status in routine clinical documentation (e.g., hard of hearing, recent falls, difficulty with home medication). These clinician-documented pretreatment functional variables (PFVs) may be predictive of outcomes among patients receiving immunotherapy. The goal of this retrospective study is to check for an association between the documentation of PFVs with overall survival (OS), progression-free survival (PFS), and the incidence of immune-related adverse events (irAEs). Methods: We created a retrospective registry of all patients who received at least one dose of an immune checkpoint inhibitor for any indication between 2/1/2011 and 4/7/2022 at a comprehensive cancer center. The investigators created a validated REDCap registry; clinical research specialist at Vasta Global captured most data. PFVs were collected by review of routine clinical documentation 30 days before or after the first dose. Patients were stratified by their number of PFVs (0,1, or 2+) and by their age (≥ or <65 years). PFVs assessed function, nutritional status and social support and were dichotomized to indicate impaired vs not with ten total categories. We used Cox proportional hazard modeling for survival analyses between the three PFV groups, calculated from the first dose of immunotherapy to disease progression, death, and last known follow-up controlling for age, BMI, smoking, and disease type with a two-sided alpha of 0.05. Results: From the overall cohort (n = 3,101), 35% had no PFVs, 32% had one PFV, and 32% had two or more PFVs; 52.5% were considered younger, and 47.5% geriatric-aged (≥65yo). PFVs were more common among the geriatric-aged population (mean 1.43 vs 0.89). The most common cancer types were lung cancer (45%), melanoma (14%), and kidney (6%). The most noted PFVs were visual impairment (26%), unintentional weight loss (22%), inability to walk a quarter block (17%), living alone (16%), and falls (14%). In the overall population, an increasing number of PFVs was associated with shorter OS. When stratified by age, the number of PFVs was associated with shorter progression-free survival (p <0.01) and overall survival (p <0.01) among the geriatric and non-geriatric populations (Table). There was no association between increasing PFVs and incidence of irAEs. Conclusions: Although often considered to be signs of aging, documentation of multiple PFVs was associated with worse OS and PFS among geriatric-aged and non-geriatric-aged populations. This study highlights the utility of routine clinical documentation on health status, including function, nutrition, and social support, to estimate survival regardless of chronologic age. [Table: see text]