PHMSA is publishing this notice to seek public comments on a report developed to support improvements in gas and hazardous liquid pipeline risk models titled "Pipeline Risk Modeling--Overview of Methods and Tools for Improved Implementation" (Pipeline Risk Modeling Report). Pipeline risk models are a foundational part of the assessment of operational pipeline risk. Federal pipeline safety integrity management (IM) regulations require pipeline operators to use risk assessments. Based on the results of pipeline inspections and failure investigation findings, both PHMSA and the National Transportation Safety Board (NTSB) have identified general weaknesses in the risk models often used by pipeline operators in performing risk assessments for their IM programs. The Pipeline Risk Modeling Report considers the major types of pipeline risk models, and the effectiveness of each type in supporting risk assessments, as applied to pipeline operator decisions.