Background: The Oncology Care Model (OCM) is a 5-year demonstration project led by the Centers for Medicare and Medicaid Services (CMS) to create a framework for the future of oncology care in the United States. More than half way through the project, our large, urban NCI-designated cancer center chose to focus on and invest in resources and personnel for patient navigation and the development of clinical pathways. Although navigation has shown to reduce emergency department (ED) visits by as much as 6% per quarter compared to non-navigated patients, sustaining it is a challenge because it is a nonbillable service. Clinical pathways are a tool to reduce care variation by addressing drug expenditures, and represent an opportunity to reduce outpatient costs by as much as 35% when patients are treated on pathway.³ Many OCM practices made similar investments and all are facing the question: How will the infrastructure and efforts developed during OCM be sustainable after the demonstration project ends?Methods: An analysis of average ED cost and utilization as well as drug expenditures was conducted using OCM feedback data (Q1-Q8). Total utilization of ED visits and ED admits were used to determine a projected annualized cost which was compared to a budgeted navigation team. Similarly, projected annualized drug expenditures were compared to the annual cost of the pathways tool. Results: We found that ED visits and ED admits would need to be reduced by 11% to cover navigation costs. Similarly, a 0.7% reduction in total drug expenditures would cover the cost of clinical pathways. The OCM data represents a timeframe prior to implementation of these programs and an average increase of 1.6% per quarter for ED admits, a 0.6% decrease in ED visits and 2.7% increase in drug expenditures. This will serve as a baseline to measure progress towards our sustainability targets. Conclusions: Long term sustainability of the infrastructure developed during OCM to support cancer care transformation will be dependent on reducing high cost and highly utilized services. Aligning impact areas with resources/tools to ensure sustainability is an approach that can help define targets for OCM practices.