| 510(k) | A premarket submission demonstrating that a device is substantially equivalent to a legally marketed predicate device. Named after Section 510(k) of the FD&C Act. |
| Accessory | An article intended to support, supplement, or complement a parent device. Accessories may require their own clearance or approval. |
| AI/AR | Additional Information / Additional Response — FDA's request for further information during a premarket review. |
| CAPA | Corrective and Preventive Action — a QMS process for identifying, investigating, and correcting product and process nonconformities. |
| CBER | Center for Biologics Evaluation and Research — the FDA centre responsible for biologics, including certain device-biologic combination products. |
| CDRH | Center for Devices and Radiological Health — the FDA centre responsible for most medical devices. |
| CFR | Code of Federal Regulations — the compilation of US federal regulations; medical devices appear primarily in Title 21 (21 CFR). |
| Class I | The lowest-risk device class; subject to general controls only. Most Class I devices are exempt from 510(k). |
| Class II | Moderate-risk devices; subject to general and special controls. Most require 510(k) clearance. |
| Class III | Highest-risk devices; require Premarket Approval (PMA). |
| Clearance | FDA's decision that a 510(k) is substantially equivalent to a predicate — results in "cleared" status. Not the same as "approved." |
| De Novo | A regulatory pathway for novel, low-to-moderate risk devices without a valid predicate. Results in a new Class I or II classification. |
| DI | Device Identifier — the portion of the UDI that identifies the version or model of a device. |
| DUF | Device User Facility — a hospital, ambulatory surgical facility, or outpatient facility with MDR reporting obligations. |
| eSTAR | Electronic Submission Template And Resource — FDA's template system for 510(k), De Novo, and PMA submissions. |
| FD&C Act | Federal Food, Drug, and Cosmetic Act — the primary US statute governing medical devices. |
| FDA | U.S. Food and Drug Administration. |
| FEI | FDA Establishment Identifier — the unique number assigned to each registered establishment. |
| GUDID | Global Unique Device Identification Database — the FDA database where UDI information is submitted and publicly searchable at AccessGUDID. |
| HDE | Humanitarian Device Exemption — an approval pathway for devices targeting diseases or conditions affecting ≤8,000 people per year in the USA. |
| IDE | Investigational Device Exemption — FDA approval to use an investigational device in a clinical study. |
| IFU | Instructions for Use. |
| IVD | In Vitro Diagnostic — a device used to examine specimens derived from the human body to detect, diagnose, or monitor disease. |
| MAUDE | Manufacturer and User Facility Device Experience — FDA's publicly searchable MDR database. |
| MDR | Medical Device Report — a mandatory report to FDA of adverse events involving medical devices. Also the regulation: 21 CFR Part 803. |
| MDUFA | Medical Device User Fee Amendments — the periodic legislation setting FDA user fees and performance goals for device review. Current version: MDUFA VI. |
| NSE | Not Substantially Equivalent — an FDA 510(k) determination that a device is not cleared; may prompt submission of a De Novo or PMA. |
| OCP | Office of Combination Products — the FDA office that assigns jurisdiction for combination products. |
| PCCP | Predetermined Change Control Plan — a submission for AI/ML-based SaMD specifying anticipated future modifications and the associated algorithm change protocol. |
| PI | Production Identifier — the portion of the UDI containing lot/batch number, serial number, manufacturing date, and/or expiration date. |
| PMA | Premarket Approval — the most stringent FDA review pathway, required for Class III devices. Results in an "approved" PMA. |
| PMOA | Primary Mode of Action — used to determine which FDA centre has jurisdiction over a combination product. |
| Product Code | A three-letter alphanumeric code assigned to a specific device type by FDA. Links to the regulation, classification, and review panel. |
| Q-Submission (Pre-Sub) | A request for informal FDA feedback prior to formal submission — formerly called a Pre-IDE or Pre-Submission. |
| QMS | Quality Management System. |
| QMSR | Quality Management System Regulation — FDA's updated QSR (21 CFR Part 820) aligned with ISO 13485:2016, effective February 2026. |
| QSR | Quality System Regulation — the former name of 21 CFR Part 820; succeeded by QMSR. |
| SaMD | Software as a Medical Device — software that performs a medical device function without being part of a hardware medical device. |
| SE | Substantially Equivalent — an FDA 510(k) determination that a device is substantially equivalent to a predicate and may be marketed. |
| Special Controls | Device-specific controls (guidance, performance standards, post-market requirements) applied to Class II devices in addition to general controls. |
| STeP | Safer Technologies Program — an FDA voluntary programme for medical devices targeting unmet medical needs but not meeting Breakthrough criteria. |
| UDI | Unique Device Identifier — a unique numeric or alphanumeric code placed on a device label. Consists of a DI and PI. |
| US Agent | A person or entity physically located in the USA who acts as FDA's primary contact for a foreign device establishment. |
| Warning Letter | An official FDA communication asserting that a company's product or practice violates the FD&C Act and requires correction. |