HHS 45 CFR 46: Protection of Human SubjectsThe HHS regulations for the protection of human subjects in research at 45CFR 46 include five subparts. Subpart A, also known as the Common Rule, provides a robust set of protections for research subjects; subparts B, C, and D provide additional protections for certain populations in research; and subpart E provides requirements for IRB registration. The Common Rule, subpart A, was revised in recent years. Access the regulatory language for all of the subparts using the links below. In addition, OHRP provides an annotated version of the Common Rule that highlights changes between the pre-2018 and 2018 versions of the Common Rule.