The US Food and Drug Administration Office of Generic Drugs has developed a question-based review (QbR) for the Chemistry, Manufacturing, and Controls (CMC) evaluation of an abbreviated new drug application (ANDA). This new QbR system incorporates quality by design and implements risk-based assessment. It recommends that ANDAs be submitted using the Common Technical Document and include the Quality Overall Summary (QOS) that addresses all the QbR questions. The main benefits of this QbR system are to (1) assure product quality through design and performance-based specifications, (2) facilitate continuous improvement and reduce CMC supplements through risk assessment, (3) enhance the quality of reviews through standardised review questions, and (4) reduce CMC review time when applicants submit a QOS that addresses the QbR questions. The QbR was partially implemented in 2006 and is being fully implemented in 2007.