Natural gas pipeline cost data collected by the Oil and Gas Journal (O&GJ) [1] for interstate pipelines constructed from 1980 through 2017 were used to develop capital cost estimating equations that are a function of pipeline diameter, length, and U.S. region. Equations were developed for material, labor, miscellaneous, and right-of-way costs, the four cost com-ponents in the O&GJ data, for six different regions of the United States (U.S.). Each equation is a function of pipeline diameter and length.Adjustment mechanisms were then developed for converting the natural gas pipeline equations into equations for estimating the costs of hydrogen pipelines. These adjust-ments were based in part on an analysis completed by the National Institute for Standards and Technology (NIST) [2,3]. The results of this work were used to update cost models in the Hydrogen Delivery Scenario Analysis Model (HDSAM) [4], developed by Argonne Na-tional Laboratory for the U.S. Department of Energy's Hydrogen Program. Our analysis shows a wide range of pipeline cost across different U.S. regions, especially with respect to labor and right-of-way costs. The developed cost formulas for hydrogen pipelines are both important and timely as hydrogen is being considered as a zero-carbon energy carrier with the potential to decarbonize all energy sectors, and the cost of hydrogen transportation is essential for techno-economic analysis of its potential use in these sectors.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.