OBJECTIVES: To estimate the potential ICU-related cost savings if in-hospital advance care planning and ICU-based palliative care consultation became standard of care for patients with chronic and serious illness. DESIGN AND SETTING: Decision analysis using literature estimates and inpatient administrative data from Premier. PATIENTS: Patients with chronic, life-limiting illness admitted to a hospital within the Premier network. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Using Premier data (2008-2012), ICU resource utilization and costs were tracked over a 1-year time horizon for 2,097,563 patients with chronic life-limiting illness. Using a Markov microsimulation model, we explored the potential cost savings from the hospital system perspective under a variety of scenarios by varying the interventions' efficacies and availabilities. Of 2,097,563 patients, 657,825 (31%) used the ICU during the 1-year time horizon; mean ICU spending per patient was 11.3k (SD, 17.6k). In the base-case analysis, if in-hospital advance care planning and ICU-based palliative care consultation were systematically provided, we estimated a mean reduction in ICU costs of 2.8k (SD, 14.5k) per patient and an ICU cost saving of 25%. Among the simulated patients who used the ICU, the receipt of both interventions could have resulted in ICU cost savings of 1.9 billion, representing a 6% reduction in total hospital costs for these patients. CONCLUSIONS: In-hospital advance care planning and palliative care consultation have the potential to result in significant cost savings. Studies are needed to confirm these findings, but our results provide guidance for hospitals and policymakers.