Background: Development of prostate cancer (PCa) metastasis, while uncommonly observed in US men, typically occurs to bone and ultimately leads to disease-specific death. The goal of this study was to estimate OS in a racially diverse cohort of military health care beneficiaries diagnosed with metastatic PCa to bone, to enhance understanding of factors such as patient race and receipt of palliative treatment, that potentially affect OS in advanced PCa patients. Methods: A retrospective cohort study was conducted, examining men consented to participate in the CPDR multi-center national database who underwent biopsy for suspicion of prostate cancer between 1989-2017 and subsequently diagnosed with bone metastasis, confirmed by bone scan, bone biopsy and/or MRI. Multivariable Cox proportional hazards (PH) analysis was used to model OS as a function of race and palliative treatment, controlling for clinical covariates. Hazard ratios (HR) and 95% Confidence intervals (CI) are reported. Results: Among 17,356 patients diagnosed with prostate cancer (PCa) between 1989 and 2017, 869 (5.0%) developed bone metastasis. Median patient age was 67 years; median follow-up time following diagnosis with bone metastasis was 2.4 years. Over one-fifth of patients (22.5%) self-reported as African American. Only 11.5% of all patients with metastasis received palliative treatment (radiation (RT) only, RT+ hormone therapy (HT), RT+HT, or RT+HT+chemotherapy). While race did not predict OS, receipt of palliative treatment was strongly predictive of better OS (p<0.0005). Conclusions: Patient race did not predict OS among those with distant metastatic PCa but receipt of palliative care and slower PSADT were critical factors in lengthening OS. This work is being extended to examine the combinations and sequencing of palliative care on OS, to provide improved patient-tailored prediction tools for men with advanced prostate cancer.