Abstract—Caltrans Seismic design criteria (SDC) provides guidelines for designing bridge columns considering the P-Delta effects in order to prevent destabilizing moments to become dominant. Caltrans SDC controls the P-Delta effects using a conservative limit for lateral displacement due to axial load, which is enforced by limiting the design target ductility demands on structural components. For columns with high P-Delta induced moments Caltrans requires the column to be analyzed using more advanced nonlinear time history analysis or the column should be redesigned to comply with Caltrans SDC guideline for ignoring the P-Delta effects. The intention of this research is to study the accuracy of the Caltrans SDC method in detecting the point which P-Delta effects can be ignored. When P-Delta effects can’t be ignored engineering firms tend to redesign the columns (use bigger section sizes or increase the reinforcement ratio) in order to prevent performing more time consuming and computationally demanding nonlinear time history analysis or Incremental Dynamic Analysis (IDA) to justify the structural behavior with inclusion of the P-Delta effects. This research performs IDA on two similar columns which one of them comply with Caltrans Criterion and the other one fails to satisfy the maximum cap for P-Delta induced moment in order to ignore the P-Delta effects. This research provides suggestions on possible improvements for the Caltrans SDC criteria for ignoring the P-Delta effects.