In an effort to better align item development to goals of assessing higher-order tasks and decision making, complex decision trees were developed to follow clinical reasoning scripts and used as models on which multiple-choice questions could be built. This approach is compatible with best-practice assessment frameworks like Evidence Centered Design and Assessment Engineering. Development of one such model within the field of Internal Medicine and an item based on the model are demonstrated, walking through the item development process step-by-step. The result is an approach extensible to any assessment involving complex decision-making and could be used to inform the entire test development process from construct development to automated item generation. Resulting models also have potential applications as teaching tools and for use in practice.