BACKGROUND & AIMS: There is growing acceptance that principles of palliative care should be integrated into the management of serious illnesses affecting the liver, such as acute-on-chronic liver failure (ACLF). However, rates, patterns, and predictors of specialty palliative care consultation among patients with ACLF have not been well-described. METHODS: We performed a retrospective cohort study of patients hospitalized with ACLF between 1/1/2008 and 12/31/2018 using the VOCAL cohort. Patients were followed until 6/2021. We used mixed-effects regression analyses to identify significant patient and facility factors associated with palliative care consultation. We examined timing of consultation, the influence of ACLF characteristics, and facility-level variation on receipt of palliative care consultation. RESULTS: We identified 21,987 patients hospitalized with ACLF, of whom 30.5% received specialty palliative care consultation. Higher ACLF grade (ACLF-2 [odds ratio (OR) 1.82, 95% CI 1.67-1.99], ACLF-3 [OR 3.06, 95% CI 2.76-3.40]), prior specialty palliative care consultation (OR 2.62, 95% CI 2.36-2.91), and hepatocellular carcinoma (OR 2.10, 95% CI 1.89-2.33) were associated with consultation. Consultation occurred latest and closest to the time of death for patients with ACLF-3 compared to ACLF-1 and ACLF-2. Significant facility-level variation in consultation persisted among patients with ACLF-3, despite adjusting for multiple patient and facility factors. CONCLUSION: In this large cohort of hospitalized patients with ACLF, specialty palliative care consultation was rare, more common in patients with higher grade ACLF, and tended to occur closer to the time of death for the sickest patients. Greater attention should be placed on earlier integration of palliative care during acute hospitalizations in patients with ACLF. IMPACT AND IMPLICATIONS: Though palliative care consultation is recommended for patients with acute-on-chronic liver failure, there is no data demonstrating how often this occurs during hospitalizations, on a population level. We found that consultation occurs in only 30.5% of patients and occurs later for patients with grade 3 acute-on-chronic liver failure. Our data should provoke clinicians to urgently consider quality improvement efforts to integrate palliative care into the management of these seriously ill patients.