This guidance is intended to assist a potential applicant who plans to develop, and submit an abbreviated new drug application (ANDA) to seek approval of, a generic version of a solid oral opioid drug product that has the potential for abuse and which references an opioid drug product with abuse-deterrent properties described in its labeling. The guidance recommends studies, including comparative in vitro studies, that should be conducted by the potential ANDA applicant and submitted to FDA in an ANDA to demonstrate that a generic solid oral opioid drug product is no less abuse-deterrent than its reference listed drug (RLD) with respect to all potential routes of abuse.