In enacting the Medical Device Amendments of 1976, Congress instituted a flexible system of regulatory controls over a vast array of health care products. Analyzing the complex statute and its legislative history, Professor Leflar finds at the law's core a structure designed to ensure the Food and Drug Administration's accountability to the public for its regulatory actions. Reviewing the history of FDA's implementation of the medical device law, however, the author demonstrates that FDA has strayed widely and, he contends, illegally from the congressionally mandated structure of public accountability. In particular, in its review of new-model medical devices in the most risk-laden class, the agency has channeled the great majority of such devices into a clearance process of its own invention. This black-box "premarket notification" process circumvents statutory requirements of public advisory committee review in open meetings, published summaries of new products' safety and effectiveness data, and justification of marketing decisions -- effectively insulating those decisions from administrative and judicial review and from adequate congressional and public oversight. Professor Leflar recognizes that the medical device law is in some respects unworkable, that FDA's departure from the congressional design has been on the whole a well-intentioned effort to increase administrative efficiency, and that the agency has undertaken noteworthy internal reforms in response to public and congressional criticism. Nevertheless, FDA's device review process departs from democratic principles. To enhance FDA's administration of the law while preserving the principle of public accountability, the author offers a number of suggestions for statutory reform.