A Certificate of Confidentiality is a document issued by the U.S. Department of Health and Human Services, granting qualified researchers legal protection from any legal or civil action that might arise from the release of confidential study information. The certificate is intended to protect the privacy of research participants by prohibiting the disclosure of their identifiable information without their express permission. It also protects researchers from being compelled to release information about their study participants, even if they are subpoenaed. There are two main types of Certificate of Confidentiality: the Common Rule Certificate, which applies to research conducted under the Common Rule (45 CFR 46), and the HIPAA Certificate, which applies to research conducted under the Health Insurance Portability and Accountability Act (HIPAA).