In 1992, the Prescription Drug User Fee Act (PDUFA, now called PDUFA I) gave the Food and Drug Administration (FDA) the authority to collect fees from the pharmaceutical industry and to use the revenue to support "the process for the review of human drug applications." That authority, which expired in 1997, has been renewed on five subsequent occasions, by PDUFA II (1997), PDUFA III (2002), PDUFA IV (2007), PDUFA V (2012), and PDUFA VI (2017). The most recent reauthorization was Title I of the Food and Drug Administration Reauthorization Act (FDARA, P.L. 115-52 ), which extends the user fee program through September 30, 2022. For FY2017, 41% of FDA's enacted total program level came from user fees; however, user fee revenue provided 63% of FDA's Human Drugs Program budget. PDUFA revenue also contributed to the Biologics Program and agency-wide headquarters and rent budgets. Congress first passed PDUFA to supplement the FDA budget outside of direct appropriations from Congress. The added funds were intended to enable the agency to increase its staff so it could finish new drug application reviews sooner, allowing both earlier patient access to new drugs and earlier industry earnings on those drugs. PDUFA I amended the Federal Food, Drug, and Cosmetic Act (FFDCA) to establish the authority and the process for collecting and using industry fees; it also required FDA and industry representatives to agree on the performance goals and procedures that the PDUFA revenue would support. This report describes (1) the origin of prescription drug user fees, (2) current law as amended by PDUFA VI, (3) the impact of PDUFA on FDA application review time and the agency's Human Drugs Program budget, and (4) PDUFA VI reauthorization process. In the late 1980s, the median time for FDA to approve a new drug application (NDA) was 29 months. Industry, consumer groups, and FDA agreed that the time from submission of a drug or biologics application to FDA's decision was unacceptably long. Patient advocates argued that a drug in review—and therefore not available for sale—could be the difference between life and death. Manufacturers argued that prolonged review times affected their ability to recoup the costs of research and development. During PDUFA I consideration, FDA estimated that each one-month delay in a review's completion cost a manufacturer an average of $10 million. FDA argued that it needed more scientists to review incoming drug applications, as well as backlogged applications, and that it had insufficient appropriations to hire additional scientists to conduct these reviews. For decades, FDA had asked Congress for permission to implement user fees. The pharmaceutical industry generally opposed them, believing the funds might go into the Treasury to reduce federal debt rather than help fund drug reviews. The pharmaceutical industry's opposition to user fees was mitigated, thus clearing a path for the 1992 law, when then FDA commissioner David Kessler worked out an arrangement that met two industry demands: (1) performance goals, which would set target completion times for various review processes, and (2) the promise that these fees would supplement—rather than replace—funding that Congress appropriated to FDA. Those steps helped persuade industry groups that the fees would reduce review times—and paved the way for Congress to authorize a revenue source that FDA had sought for over 20 years. PDUFA I—and the subsequent PDUFA II, PDUFA III, PDUFA IV, PDUFA V, and PDUFA VI—authorized the collection of prescription drug user fees and the use of that revenue for specified activities. Prior to marketing a drug, a manufacturer must submit to FDA a new drug application (NDA) demonstrating that the drug is safe and effective for its intended use. FDA reviews each NDA with three major concerns: (1) safety and effectiveness in the drug's proposed use, (2) appropriateness of the proposed labeling, and (3) adequacy of manufacturing methods to ensure the drug's identity, strength, quality, and purity. PDUFA I authorized FDA to use the fee revenue to fund the "process for the review of human drug applications" and defined what that process encompassed. With subsequent reauthorizations, Congress has amended that definition to expand the scope of activities covered by PDUFA. The upper portion of Figure 1 depicts the research and development path of a new drug, from basic research through preclinical development and testing on animals, clinical development in trials on human subjects as an investigational new drug (IND), FDA review of the NDA, and, finally, the postapproval period in which the drug is marketed. The figure's lower portion illustrates the segments of this path during which FDA may use PDUFA revenue to support its activities and how the scope of those activities has been expanded with subsequent reauthorizations. PDUFA I (FY1993-FY1997). PDUFA I allowed fee revenue to fund "activities necessary for the review of human drug applications and supplements." In addition to the actual review of applications, it covered activities such as letters from FDA to applicants outlining deficiencies in their applications, facility inspections as part of pending approval applications, and monitoring of research necessary for the review of applications. All those activities fit within the timeframe from when a manufacturer submits an NDA until FDA makes its decision on that application. PDUFA II (FY1998-FY2002). PDUFA II expanded the range of activities for which FDA could use prescription drug user fee revenue to include those related to preclinical and clinical trial phases of a new drug's development. PDUFA III (FY2003-FY2007). PDUFA III extended the range of activities for which FDA could use prescription drug user fee revenue to include three years into the postapproval and marketing period. It allowed FDA to use PDUFA revenue for the collection, development, and review of postmarket safety information for up to three years postapproval (for drugs approved after October 1, 2002). That change allowed the agency to double the number of staff monitoring side effects of drugs already on the market. It also allowed FDA to use fees to develop databases documenting drug use. PDUFA IV ( FY2008-FY2012). PDUFA IV removed the three-year limitation on postapproval activities and again expanded the list of postmarket safety activities that the fees could support. New items on the list included developing and using adverse-event data-collection systems, including information technology systems; developing and using improved analytical tools to assess potential safety problems, including access to external databases; implementing and enforcing new FFDCA requirements relating to postapproval studies, clinical trials, labeling changes, and risk evaluation and mitigation strategies; and managing adverse event reports. PDUFA V (FY2013-FY2017) and PDUFA VI (FY2018-FY2022) . PDUFA V and VI did not change the definition of the "process for the review of human drug applications," thus maintaining the PDUFA IV scope of activities that fees could support. PDUFA I connected prescription drug user fees to performance goals and targets. FDA negotiated those goals and targets with the pharmaceutical industry and presented them to Congress in the form of a letter from the Department of Health and Human Services Secretary (the Secretary), to which the legislation referred without putting the letter's language directly into law (the FFDCA). PDUFA II and III continued that procedure, again referring to the letter ("PDUFA Reauthorization Performance Goals and Procedures"). However, in 2007, PDUFA IV codified the requirements for a goals letter, consultation and public communication, and other processes as FFDCA Section 736B. Each five-year reauthorization sets a total amount of fee revenue for the first year and provides a formula for annual adjustments to that total based on inflation and workload changes. PDUFA I through V had required that three types of fees each contribute one-third of the fee revenue every year: application fees, establishment fees, and product fees. PDUFA VI establishes a new user fee structure, eliminating the product and establishment fees and adding a program fee , to provide 80% of the total fee revenue. PDUFA VI continues the application fee , to provide 20% of the total fee revenue, while eliminating the fee for a supplemental application. Application fee : The sponsor of an application (usually the manufacturer) must pay a fee for FDA review each time it submits an NDA or BLA. Program fee: The sponsor of an application must pay an annual program fee for each prescription drug product that is identified in an application. According to CDER Director Janet Woodcock's March 2017 testimony at a House Energy and Commerce Committee hearing on the then proposed PDUFA VI, FDA proposes to enhance the program fee structure and related mechanisms, to achieve increased predictability, stability, and efficiency. The current overall PDUFA fee structure and the fee setting process were established in 1992. Both FDA and industry recognize that updating some elements of the fee structure and the fee setting process will enhance administrative efficiency and the predictability and stability of fee amounts and revenues and improve FDA's ability to engage in long-term financial planning... Under PDUFA I through V, fee revenues were adjusted for inflation and to reflect changes in FDA's workload for the process for the review of human drug applications. The workload adjustment calculation was based on a weighted average of the change in the total number of human drug applications, commercial IND applications, efficacy supplements, and manufacturing supplements submitted. For additional information about fee adjustments prior to PDUFA VI, see CRS Report R42366, Prescription Drug User Fee Act (PDUFA): 2012 Reauthorization as PDUFA V .