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A study of how method roles evolve during the lifetime of a software system is presented. Evolution is examined by analyzing when the stereotype of a method changes. Stereotypes provide a high-level categorization of a method's behavior and role, and also provide insight into how a method interacts with its environment and carries out tasks. The study covers 50 open-source systems and 6 closed-source systems. Results show that method behavior with respect to stereotype is highly stable and constant over time. Overall, out of all the history examined, only about 10% of changes to methods result in a change in their stereotype. Examples of methods that change stereotype are further examined. A select number of these types of changes are indicators of code smells.