Site Feedback

Title 21

Displaying title 21, up to date as of 7/17/2026. Title 21 was last amended 7/09/2026.
eCFR Content

The Code of Federal Regulations (CFR) is the official legal print publication containing the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. The Electronic Code of Federal Regulations (eCFR) is a continuously updated online version of the CFR. It is not an official legal edition of the CFR.

Learn more about the eCFR, its status, and the editorial process.

Title 21Food and DrugsPart / Section
Chapter IFood and Drug Administration, Department of Health and Human Services1 – 1299
Subchapter HMedical Devices800 – 898
Part 866Immunology and Microbiology Devices866.1 – 866.6110
Subpart AGeneral Provisions866.1 – 866.9
§ 866.1Scope.
§ 866.3Effective dates of requirement for premarket approval.
§ 866.9Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).
Subpart BDiagnostic Devices866.1620 – 866.1700
§ 866.1620Antimicrobial susceptibility test disc.
§ 866.1640Antimicrobial susceptibility test powder.
§ 866.1645Fully automated short-term incubation cycle antimicrobial susceptibility system.
§ 866.1650A cellular analysis system for multiplexed antimicrobial susceptibility testing.
§ 866.1655System for detection of microorganisms and antimicrobial resistance using reporter expression.
§ 866.1700Culture medium for antimicrobial susceptibility tests.
Subpart CMicrobiology Devices866.2050 – 866.2952
Subpart DSerological Reagents866.3010 – 866.4001
Subpart EImmunology Laboratory Equipment and Reagents866.4070 – 866.4900
Subpart FImmunological Test Systems866.5040 – 866.5980
Subpart GTumor Associated Antigen immunological Test Systems866.6000 – 866.6110