This congressional testimony by Doug Koplow (President, Earth Track) to the the Subcommittee on Energy of the Committee on Energy and Commerce of the US House of Representatives addresses US tax policy and its effects on markets, prices and consumers. It argues that all key support mechanisms must be evaluated to properly assess the market, environmental, and fiscal impacts of energy subsidies; that subsidies to conventional fuels are often more difficult to quantify than those to renewables, but are nonetheless large and long‐standing; and finally that simple changes to policy structures can greatly improve subsidy efficiency and transparency. The testimony is available to download on the website of the US House of Representatives.