This paper summarizes the results of a sensitivity study conducted on corrosion clusters on a steel pipeline, specifically (1) the change in cluster effective length as the individual anomalies that make up the cluster grow and (2) the effect of changes in effective length on the remaining life calculated using deterministic methods. Two growth scenarios are considered: clusters that grow at the same rate along the cluster versus clusters that grow at a depth-based corrosion growth rate (e.g., deeper areas grow faster than shallower areas). The study shows that, in both scenarios, the effective lengths of long clusters shrink with growth. Examples demonstrate the impact of the results for a semi-elliptically shaped anomaly. The change in effective length and the corresponding change in critical or maximum depth led to an increase in calculated remaining life of 20% to 40% for the cases studied.