Glossary
Glossary
The terms you will meet in an FDA submission, defined in plain English, each with the regulation or guidance it comes from.
Not every term FDA uses is here. These are the ones that come up in a device submission and that people most often ask about.
21 CFR; FDA guidance documents
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- 510(k)Guide page
- A premarket notification showing a device is substantially equivalent to one already legally marketed.21 CFR Part 807, Subpart E
- 510(k) clearance vs. De Novo grantGuide page
- A 510(k) clearance rests on comparison to an existing predicate; a De Novo grant creates a brand-new classification because no predicate exists.FD&C Act §513(f)(2) (De Novo); §510(k) (510(k))
- 513(g) request
- A formal, paid request for FDA's written opinion on how a device is classified or which pathway applies — informational, not a submission decision.FD&C Act §513(g); 21 CFR 807 Subpart A
- 522 postmarket surveillance order
- FDA's authority to require a manufacturer to actively track a device's real-world performance after clearance or approval.FD&C Act §522
A
- Abbreviated 510(k)
- A 510(k) that leans on an FDA guidance document, special control, or recognized consensus standard instead of full head-to-head predicate testing.FDA Guidance: The 510(k) Program
- Acceptance reviewGuide page
- FDA's confirmation that a submission is complete enough to enter substantive review — the modern, lighter version of RTA.FDA Guidance: Acceptance Review
- Acceptance review and Refuse to AcceptGuide page
- The screen a submission passes first, and the 180-day deadline behind it.FDA RTA guidance
- Adaptive algorithm
- An algorithm that can change its behavior after deployment — the reason PCCP exists, so those changes don't each need a fresh submission.FDA Discussion Paper: Proposed Regulatory Framework for AI/ML-Based SaMD
- Additional Information (AI) requestGuide page
- FDA's request for more data during review, which pauses the review clock until you respond — sometimes called a deficiency letter.21 CFR 807.87(l); MDUFA V Commitment Letter
- Adverse event
- An unexpected medical incident possibly linked to device use — the trigger for a Medical Device Report if it meets the reportability criteria.21 CFR Part 803
- Adverse event reportingGuide page
- What must be reported to FDA, by whom, and within what deadline.21 CFR 803
- ASCA
- FDA's Accreditation Scheme for Conformity Assessment — labs accredited under ASCA get a smoother review path for the standards it covers.FDA ASCA Pilot Program
B
- Bench testing
- Non-clinical performance testing done in a lab setting rather than on human subjects — the most common evidence type in a 510(k).FDA Guidance: The 510(k) Program
- Biocompatibility
- Evidence a device's materials don't cause an unacceptable biological reaction where they contact the body, per ISO 10993.ISO 10993-1
- Breakthrough Devices Program
- Voluntary FDA program giving more effective and novel devices priority review and closer FDA interaction — not a shortcut around the evidence bar.FD&C Act §515B
C
- CDRH
- FDA's Center for Devices and Radiological Health — the branch that regulates medical devices.FD&C Act, device provisions
- CDRH PortalGuide page
- FDA's Customer Collaboration Portal — where submissions are uploaded and their status tracked.FDA CDRH Customer Collaboration Portal
- Class I
- FDA's lowest-risk device tier — general controls only, and most are exempt from premarket review entirely.FD&C Act §513(a)(1)(A)
- Class II
- FDA's moderate-risk tier — general controls plus special controls, and the class that typically needs a 510(k).FD&C Act §513(a)(1)(B)
- Class III
- FDA's highest-risk tier — life-sustaining, implantable, or high-risk devices, generally requiring PMA.FD&C Act §513(a)(1)(C)
- Classification panel
- One of FDA's medical specialty panels (e.g. Cardiovascular, Orthopedic) that device classification regulations are organized under.21 CFR Part 862–892 (organized by panel)
- Cleared vs. approvedGuide page
- "Cleared" means a 510(k) showed substantial equivalence; "approved" means a PMA showed independent safety and effectiveness. They are not interchangeable.FD&C Act §510(k) vs. §515
- Clinical Decision Support
- Software that helps a clinician make a decision — regulated as a device unless it meets specific criteria letting the clinician independently review the basis for the recommendation.FD&C Act §520(o)(1)(E)
- Clinical evaluation
- Assessment of clinical data relevant to a device — required for PMA, and occasionally needed in a 510(k) when bench data can't bridge to the predicate.21 CFR Part 812 (for investigational use)
- Combination product
- A product combining a device with a drug or biologic — regulated by whichever center has jurisdiction over its "primary mode of action."21 CFR Part 3
- Consensus standard
- A voluntary standard FDA has formally recognized — citing one in your submission can substitute for describing the same evidence from scratch.FDA Recognized Consensus Standards Database
- Contract manufacturer
- A facility that manufactures a device to another company's specifications — registers, but doesn't usually hold the 510(k) itself.21 CFR Part 807, Subpart B
- Correction vs. removal vs. market withdrawalGuide page
- A correction fixes a device in the field; a removal takes it out of the field or market; a market withdrawal is a minor action for a violation FDA wouldn't otherwise act on.21 CFR Part 806; 21 CFR 7.3
- Cybersecurity (524B)
- The statutory cybersecurity requirements for connected devices — an SBOM, a plan to monitor and patch vulnerabilities, and more.FD&C Act §524B
D
- De Novo
- The pathway for a novel, low-to-moderate-risk device with no valid predicate — grants create a new classification others can use as one.21 CFR 860.200; FD&C Act §513(f)(2)
- De Novo classificationGuide page
- The route when no predicate exists, and how it differs from a 510(k).FD&C Act 513(f)(2)
- Declaration of Conformity
- A signed statement that a device meets a recognized consensus standard, submitted in place of the full underlying test data.FD&C Act §514(c)
- Design controls
- The formal, documented process for developing a device — requirements, design, verification, validation — required under the QMSR.21 CFR 820.30 (QMSR)
- Design History File (DHF)
- The compiled record of a device's entire design process — proof the design controls were actually followed.21 CFR 820.30(j)
- Device classificationGuide page
- Class I, II and III, and how the product code decides which one applies.21 CFR 860; 862–892
- Device History Record (DHR)
- The manufacturing record proving a specific batch or unit was made according to the DMR.21 CFR 820.184
- Device identifier vs. production identifierGuide page
- The device identifier (DI) identifies the make and model; the production identifier (PI) identifies the specific lot, batch, serial number, or expiration date.21 CFR 830.3
- Device labelingGuide page
- What must appear on a device label, and the claims that cannot.21 CFR 801
- Device listing
- Telling FDA which specific devices your registered establishment makes or distributes — separate from, and required alongside, registration.21 CFR Part 807, Subpart B
- Device Master Record (DMR)
- The complete set of specifications for how to manufacture the finished device.21 CFR 820.181
E
- eCopy
- The older electronic-copy submission format eSTAR has mostly replaced for 510(k)s.FDA Guidance: eCopy Program
- Establishment registration
- The annual FDA registration required of any facility that manufactures, imports, or distributes devices in the US.21 CFR Part 807, Subpart B
- eSTARGuide page
- Mandatory for 510(k)s since October 2023 and De Novo since October 2025.FDA eSTAR guidance
- Exempt device
- A device whose product code is excused from premarket notification — most Class I devices, and some Class II.21 CFR 807.85; classification regulations, §8xx.9
- Exemption limitations (§8xx.9)
- The clause at the end of most classification regulations that claws back a device's exemption if certain higher-risk features apply.21 CFR §xxx.9, per classification part
F
- FDA medical device user feesGuide page
- Every MDUFA fee for FY2026 and FY2027, with the date each takes effect.MDUFA
- Foreign manufacturer
- A manufacturer based outside the US — can submit a 510(k) directly, but must have a US Agent on file.21 CFR 807.40
- Form 483
- The list of inspectional observations an FDA investigator hands you at the end of an establishment inspection — not itself an enforcement action.FDA Inspection Guide
G
- General controls
- The baseline requirements every device is subject to — registration, listing, labeling, good manufacturing practice — regardless of class.FD&C Act §513(a)(1)(A); 21 CFR Part 800s
- GUDID
- FDA's Global Unique Device Identification Database — the public repository every UDI record gets submitted to.21 CFR Part 830, Subpart E
H
- Hold
- The review clock stops while a submission is on hold — for an AI response, a user fee payment, or another open item.MDUFA V Commitment Letter
- Human factors
- Usability engineering evidence that intended users can operate the device safely and as intended.FDA Guidance: Applying Human Factors and Usability Engineering to Medical Devices
I
- IDE (Investigational Device Exemption)
- Permission to use an unapproved device in a clinical study, exempting it from the requirements that would otherwise apply to a marketed device.21 CFR Part 812
- IEC 60601
- The standard series for electrical safety and essential performance of medical electrical equipment.IEC 60601-1
- IEC 62304
- The standard for medical device software lifecycle processes — the framework FDA expects behind any software-containing device.IEC 62304:2006
- IEC 62366
- The standard for applying usability engineering to medical devices — the basis for a human factors file.IEC 62366-1:2015
- IFU (Instructions for Use)
- The labeling that tells users how to use the device safely and as intended.21 CFR 801.109
- Indications for use
- The specific disease, condition, or population the device is intended for — a narrower statement filed as part of a 510(k) or PMA.21 CFR 814.20(b)(3)(i); FDA Form 3881
- Initial importer
- The first US entity that takes commercial possession of a device from abroad — has its own registration and listing duties.21 CFR 807.3(e)
- Intended use
- What you claim the device is for — the single factor that decides whether and how FDA regulates it, independent of the underlying technology.21 CFR 801.4
- Intended use vs. indications for useGuide page
- Intended use is the broad general purpose of the device; indications for use is the specific disease, condition, or population it's cleared for.21 CFR 801.4; 21 CFR 814.20(b)(3)(i)
- Interactive review
- An informal, fast back-and-forth with the reviewer to resolve a minor issue without triggering a formal AI request.MDUFA V Commitment Letter
- ISO 10993
- The standard series for biological evaluation of medical devices — required for any device that contacts the body.ISO 10993 series
- ISO 13485
- The international quality management system standard for medical devices, now the backbone of FDA's own QMSR.ISO 13485:2016
- ISO 14971Guide page
- The international standard for medical device risk management — identifying hazards, harms, and controls.ISO 14971:2019
K
- K-number
- The identifier FDA assigns to a cleared 510(k), e.g. K253001 — your proof of clearance.21 CFR 807.92
L
- Labeler
- The entity whose name appears on the device label and who is responsible for its UDI submission to GUDID.21 CFR 830.3
- Letter to FileGuide page
- Internal documentation that a device change was assessed and didn't require a new 510(k) — kept on file, not sent to FDA.FDA Guidance: Deciding When to Submit a 510(k) for a Change to an Existing Device
- Locked algorithm
- An algorithm that produces the same result every time for the same input — doesn't change or learn after clearance without a new submission.FDA Discussion Paper: Proposed Regulatory Framework for AI/ML-Based SaMD
M
- MAUDE
- FDA's public database of medical device adverse event reports — searchable, and useful for predicate due diligence too.FDA MAUDE Database
- MDR reporting
- The mandatory reporting of deaths, serious injuries, and certain malfunctions to FDA within set deadlines.21 CFR Part 803
- MDUFAGuide page
- The Medical Device User Fee Amendments — the law setting FDA's device review fees and review-time goals.FD&C Act §737–738
N
- Not Substantially Equivalent (NSE)Guide page
- FDA's finding that a 510(k) failed to establish substantial equivalence — the device can't market via that submission.21 CFR 807.100(a)
O
- Official Correspondent
- The single named contact FDA communicates with about a submission — usually who receives AI requests and holds.21 CFR 807.20
P
- PCCP (Predetermined Change Control Plan)Guide page
- A pre-authorized plan for how an AI/ML device's model can change over time, without filing a new submission for each update.FDA Guidance: Predetermined Change Control Plans, 2025
- PMA (Premarket Approval)
- FDA's most demanding pathway — independent review of clinical evidence of safety and effectiveness, for Class III devices.21 CFR Part 814
- Predicate deviceGuide page
- A legally marketed device you compare yours to in a 510(k) to demonstrate substantial equivalence.FD&C Act §513(i)(1)(A)
- Predicate devicesGuide page
- What qualifies as a predicate, and why intended use governs the choice.21 CFR 807.92
- Predicate vs. reference deviceGuide page
- The predicate carries the primary substantial-equivalence argument; a reference device only supports one specific characteristic.FDA Guidance: The 510(k) Program
- Premarket approval
- The formal name for a PMA — an independent FDA finding of safety and effectiveness, not a comparison to an existing device.FD&C Act §515; 21 CFR Part 814
- Premarket notificationGuide page
- The formal name for a 510(k) — notifying FDA of intent to market, not asking for approval.FD&C Act §510(k)
- PreSTARGuide page
- FDA's interactive PDF template for Pre-Submission (Q-Sub) requests — the eSTAR equivalent for pre-submission interactions.FDA Guidance: PreSTAR
- Product codeGuide page
- FDA's specific category for your device type — decides your class, guidance documents, and special controls.21 CFR Part 862–892 (device classification regulations)
Q
- QMSRGuide page
- The quality system rule, in force since February 2026, and why an ISO 13485 certificate is not enough.21 CFR 820
R
- Real-world evidence
- Clinical evidence about device use or outcomes derived from real-world data, rather than a traditional prospective trial.FDA Guidance: Use of Real-World Evidence
- Reasonable assurance of safety and effectiveness
- The evidentiary bar behind PMA approval — not zero risk, but enough valid evidence that the benefits outweigh the risks for the intended use.FD&C Act §513(a)(3)
- Recall (Class I / II / III)
- FDA's severity tiers for a correction or removal — Class I is reasonable probability of serious harm or death; Class III is unlikely to cause harm.21 CFR 7.3(m)
- Recall vs. safety noticeGuide page
- A recall is a formal correction or removal action under FDA's regulatory framework; a "safety notice" is often just how a company chooses to communicate about it — not a distinct regulatory category.21 CFR Part 806; 21 CFR 7.3(m)
- Reference device
- A second device cited in a 510(k) to support one specific characteristic — not the primary predicate the SE argument rests on.FDA Guidance: The 510(k) Program
- Refuse to Accept (RTA)Guide page
- FDA's pre-review completeness checklist — historically bounced a large share of paper-era submissions before eSTAR automated the check.FDA RTA Checklist for 510(k)s
- Registration vs. listingGuide page
- Registration identifies the facility; listing identifies which specific devices that facility makes or distributes. Both are required, and neither substitutes for the other.21 CFR Part 807, Subpart B
- Regulation number
- The specific 21 CFR section that defines your device type, e.g. 21 CFR 870.2300 for a cardiac monitor.21 CFR Parts 862–892
- Relabeler
- An entity that changes a device's label without otherwise altering the device — has its own registration obligations.21 CFR 807.3(bb)
- Remanufacturer
- An entity that processes a finished device to significantly change its performance, safety, or intended use — treated much closer to a manufacturer than a repair shop.21 CFR 820.3(w) (QMSR)
- Repackager
- An entity that repackages a finished device without changing the label content — distinct role from relabeling.21 CFR 807.3(cc)
S
- Safer Technologies Program (STeP)
- Like Breakthrough, but for devices that improve safety for a less-serious condition rather than treating a life-threatening one.FDA Guidance: Safer Technologies Program for Medical Devices
- SaMD (Software as a Medical Device)
- Software intended to perform a medical function on its own — not embedded in or driving a hardware device.IMDRF SaMD Working Group definitions
- Shelf life
- The validated period a device (especially sterile or packaged) remains safe and effective to use.FDA Guidance: Shelf Life of Medical Devices
- SiMD (Software in a Medical Device)
- Software that's embedded in or drives a hardware device — as opposed to SaMD, which stands on its own.FDA Digital Health Software Precertification
- Small Business DeterminationGuide page
- The $100 million threshold, form 3602N, and the $21,490 it saves.FD&C Act 738
- Small Business Determination (SBD)Guide page
- FDA certification qualifying a company for reduced MDUFA fees — must be applied for before filing, not retroactively.FDA Small Business Determination Program
- Special 510(k)
- A faster 510(k) path for modifying your own already-cleared device, when design controls can verify the change without new testing.FDA Guidance: The Special 510(k) Program
- Special controls
- Extra, device-specific requirements for Class II devices — often a mandatory performance standard or specific labeling FDA has identified for that product code.FD&C Act §513(a)(1)(B)
- Special vs. Abbreviated 510(k)Guide page
- Special 510(k) is for modifying your own already-cleared device; Abbreviated 510(k) is for any device (yours or not) that can lean on a recognized standard or guidance instead of full predicate testing.FDA Guidance: The Special 510(k) Program; FDA Guidance: The 510(k) Program
- Specification developer
- The party who designs a device's specifications but has it manufactured by someone else under contract.21 CFR 807.3(o)
- Split predicate
- Using one predicate for intended use and a different one for technological characteristics — allowed, but it invites more scrutiny than a single clean predicate.FDA Guidance: The 510(k) Program
- Sterilization validation
- Testing proving a sterilization method reliably achieves the required sterility assurance level for the device.ISO 11135 / ISO 11137 / ISO 17665, per method
- Substantial equivalenceGuide page
- The legal test a 510(k) must pass, and how FDA applies it.FD&C Act 513(i)
- Substantive InteractionGuide page
- FDA's first real signal on your submission, targeted within roughly 60 days under the MDUFA goals — not the final decision.MDUFA V Commitment Letter
T
- Technical screeningGuide page
- The lighter completeness check eSTAR submissions get today in place of a full RTA bounce.FDA Guidance: eSTAR
- The Q-Submission ProgramGuide page
- Asking FDA a question before you build, and when the delay is worth it.FDA Q-Sub guidance
- Third Party ReviewGuide page
- Which devices are eligible, and why the 30-day figure is not what it looks like.FD&C Act 523
- Traditional 510(k)
- The default 510(k) type for a new device or a significant modification — full comparison to a predicate, no shortcuts.21 CFR 807.87
U
- UDI (Unique Device Identifier)
- A standardized barcode identifying a device by make and model — required on labels and packaging for most devices.21 CFR Part 830
- UDI and GUDIDGuide page
- Who counts as the labeler, and what goes into the public database.21 CFR 830; 801 subpart B
- US Agent
- The US-based point of contact a foreign manufacturer must designate for FDA communications — required, not optional, for non-US establishments.21 CFR 807.40
- User fee hold
- FDA won't begin review until the MDUFA fee has cleared — payment takes days, so leaving it late can stall a submission before review even starts.FDA MDUFA Fee Payment
W
- Warning letter
- A formal FDA notice that violations found (often during an inspection) need correcting, with a real prospect of stronger enforcement if they aren't.FDA Regulatory Procedures Manual, Ch. 4
- Withdrawal
- Pulling a submission before FDA decides — often to fix a problem and refile, rather than risk an NSE on the record.21 CFR 807.87
- Work day vs. calendar dayGuide page
- FDA deadlines mix both — a "working day" excludes weekends and federal holidays, a "calendar day" doesn't.21 CFR 803.3 (calendar day); 21 CFR 806.10 (working day)