Risk adjustment models play a critical role in guiding clinical care, adjusting case mix in research and supporting health services planning and financing, including payment adjustments based on patient complexity. However, these models, such as the Elixhauser Comorbidity Measure, often focus solely on comorbid illnesses and may not fully capture a patient’s medical complexity. This is especially pertinent in Israel, where hospitals are reimbursed a fixed fee per day, irrespective of patient complexity.