We test and cannot reject the hypothesis that retail pricing of natural gas is transparent for commercial and residential customers served by regulated local distribution companies in the United States. The periods of adjustment to a wholesale price change are 1.54 months for the commercial price and 1.69 months for the residential price. These findings support the view that regulated local distribution companies quickly adjust retail prices to fully capture any change in the wholesale natural gas price. Copyright © 2013 John Wiley & Sons, Ltd.