Background: Patients with hematologic malignancies are less likely to receive outpatient palliative care (OPC) compared to patients with other cancer types. Little is known about the characteristics or health care utilization of patients with hematologic malignancies who are co-managed by OPC. In this study, we evaluated referral patterns and health care utilization of patients with hematologic malignancies who were seen in an embedded OPC clinic. Methods: We conducted a retrospective cohort study of patients who established care with an embedded OPC nurse practitioner from 3/2016 – 5/2020 at a quaternary academic medical center. We obtained information about patients’ demographics, clinical characteristics, and reasons for referral to OPC from the electronic health record. Information about costs and health care utilization were provided by our finance team. For patients who were followed by OPC for at least 6 months, we used two-tailed t-tests to compare the number of hospitalizations and emergency department (ED) visits, as well as total costs, for the 6 months before and the 6 months after initiating OPC. This was approved by the UCSF IRB. Results: A total of 120 patients received OPC. Median age was 59 years (range 24-89), 48% were female, and 64% were Non-Hispanic White. Myeloma was the most common cancer (n = 50/120, 41.7%), followed by aggressive lymphoma (n = 21/120, 17.5%), and acute myeloid leukemia (n = 18/120, 15%). The primary reason for referral was for symptom management, such as pain (60%, n = 72/120), mood symptoms (12.5%, n = 15/120), and fatigue (7.5%, n = 9/120). Ten percent (n = 12/120) were referred for goals of care conversations prior to stem cell transplant (SCT). An advance directive was on file for 29% (n = 35/120) of patients, of which 34% (n = 12/35) were completed after OPC enrollment. Of the 38 patients who died, the median time from PC enrollment to death was 15.3 months, and 39% died on hospice. For the 65 patients who were followed by OPC for at least 6 months, the total number of inpatient hospitalizations, excluding SCT, went from 0.82 to 0.54 (p = 0.11) per person in the 6 months before compared to the 6 months after initiating OPC. ED visits went from 0.28 to 0.18 (p = 0.33). The total direct cost of inpatient hospitalizations, excluding SCT, decreased from $43,428 to $13,226 (p = 0.01), and the cost of ED visits went from $640 to $297 (p = 0.32) per person. Conclusions: There is an important role for embedded OPC for patients with hematologic malignancies, long before the end-of-life period, to manage symptoms and support decision-making. OPC is associated with a trend towards lower health care utilization and decreased hospitalization costs. Prospective studies are warranted to further explore the impact of OPC on symptoms and patient/caregiver experience, as well as to clarify how OPC impacts health care utilization.