Background: The provision of adequate nutritional care in outpatient cancer centers was the focus of a 2016 NAS Workshop, “Assessing Nutrition Care in Outpatient Oncology.” Here we report our internal project evaluating ongoing documentation of a malnutrition screening tool (MST) at 3 national cancer centers (CC). Methods: Screening scores from a validated 2 question MST scale were entered into the EMR. Questions probe for: 1) unintentional weight loss; and 2) eating poorly because of a decreased appetite. A score of ≥ 2 indicated nutrition risk. De-identified oncology clinic visit data were examined monthly to assess MST utilization and scores for radiation and medical oncology patients across the CC’s. Results: Approximately two-thirds (67%) of unique medical oncology patients that visited the CC’s had documented MST data with 9% (n = 144,129) scoring at nutritional risk. MST completion rates were higher in radiation oncology clinics secondary to staff education. Of those that had a valid MST score in radiation clinics, 13% (n = 23,202) of MST scores indicated nutritional risk. Conclusions: The MST is a valid malnutrition screening tool for outpatient oncology patients, yet this tool is not uniformly being utilized nationally. Consistent use of the MST in the electronic medical record and leveraging data on utilization are needed to inform staff compliance, consistency in care, future dietitian staffing patterns, cost/benefit analysis, and health outcomes for oncology patients.