A scientific workforce with cutting-edge skills is critical for the ability of the U.S. Environmental Protection Agency to carry out its mission to protect human health by identifying environmental hazards, evaluating risks to public health and ecosystems, and formulating effective methods for pollution control and prevention. To aid in the selection and hiring of premier scientists and engineers, in 2006, EPA first sought the ability to directly recruit world-renowned scientists and engineers from academia, private industry, and other government agencies under Title 42, Section 209, of the U.S. Code. Title 42 authorizes federal agencies to appoint highly qualified scientists and engineers outside of standard civil service positions. Congress reauthorizes the EPA Title 42 authority in 5-year increments.To guide decisions about the future of the program, Congress asked the National Academies to review past and current EPA use of Title 42 hiring authority and how the program might be improved. The report finds that EPA has used its limited Title 42 authority effectively since 2006 and that Title 42 authority has enabled the hiring of effective scientific leadership and improved the scientific capability and capacity to support the Agency mission. Furthermore, the report finds that Title 42 can help the agency in addressing future environmental complexities. In continuing to enhance its scientific workforce and maintain a position at the forefront of evolving scientific knowledge, EPA would benefit from Congressional approval for permanent Title 42 authority.