When Ben Wyatt first arrives in Pawnee to fix the town's budget, he is an Indiana state auditor.
Ben enters the story as part of a state team sent to deal with Pawnee's severe financial crisis. His assignment is not to run the town's budget department or serve as its treasurer; he is auditing the municipality on behalf of the state. Chris Traeger accompanies him as the state auditor's superior and colleague.
The budget crisis initially puts Ben at odds with Leslie Knope and the Parks Department, since his work involves cutting spending and examining how Pawnee operates. Their professional conflict gradually develops into mutual respect and, eventually, a relationship and marriage.
Ben's later career changes are a frequent source of confusion. After his state-auditor assignment, he works in Pawnee, becomes involved in political campaigns, and later pursues congressional and federal political ambitions. Those later roles do not change the job he holds when he first arrives in the series.