A therapy program may be modified based on information indicative of a change in a therapy field, which may represent a region of a patients tissue to which therapy is delivered. Upon receiving information indicative of a therapy field change, an algorithmic model of a present therapy field may be generated and compared to an algorithmic model of a baseline therapy field, which indicates a therapy field that provides efficacious therapy to the patient. If a characteristic of the present therapy field differs from the baseline therapy field model, the current therapy program may be modified. In another example, upon receiving information indicative of a therapy field change, the current therapy program may be modified, and an algorithmic model of a therapy field based on the modified therapy program may be compared to a baseline therapy field model to determine whether the modified therapy program is a suitable alternative.
