Access to the best available science allows federal decision makers to craft policies that protect our health and safety and the environment. Unfortunately, censorship of scientists and the manipulation, distortion, and suppression of scientific information has threatened the federal scientific enterprise in recent years. This serious problem has sparked much debate, but few have analyzed the key driver of political interference in federal science: the inappropriate influence of companies with a financial stake in the outcome. This influence affects not only the science used in decision making, but also public opinion and the decision-making process itself. By better understanding how corporations influence the use of science in federal decision making, we can both hold companies and policy makers accountable for their actions and ensure that the nation develops science-based policies that serve the public interest. The first chapter of this report explores the numerous methods corporate interests employ to inappropriately influence how the federal government uses science to make decisions. The second chapter provides an overview of the steps the Obama administration has taken to restore scientific integrity to federal policy making. The third chapter focuses on the federal reforms still essential to ensure that authoritative and independent scientific information informs policies designed to protect public health and the environment. Recognizing that solving this problem extends far beyond what the government can accomplish alone, we also suggest broader reforms that corporations, the scientific community, academic institutions, news media, and the courts can pursue to ensure transparency and accountability in the use of science.