Written and maintained by CASRAI Editorial Board
Last updated
General information only, not medical or regulatory advice. Regulatory statements are drawn from the FDA and eCFR texts cited under Sources.
Short answer
Kitting is the light assembly of separate items into one ready-to-use unit before production or shipment. In warehouse logistics the items can be any parts or tools. In medical and laboratory supply, FDA uses the related term convenience kit for two or more medical devices packaged together for the user’s convenience, and the party that assembles one carries defined regulatory responsibilities.
Definition and scope
Two definitions matter, and they are not the same thing.
The logistics meaning
Penske Logistics’ glossary defines kitting as “the light assembly and preparation of units, such as components, parts or tools, ahead of production or shipment.” Its example is a warehouse that packs several surgical instruments into one bag so the kit arrives assembled, instead of delivering separate bags of scalpels and scissors. This is a fulfilment concept: the definition does not address device regulation.
The regulatory meaning for medical devices
21 CFR 801.3 defines a convenience kit as “two or more different medical devices packaged together for the convenience of the user.” FDA’s 1997 Convenience Kits Interim Regulatory Guidance describes the typical case as legally marketed devices “simply being assembled in kit form” for the purchaser’s convenience, and says that for its purposes the terms kit, set and tray are synonymous. A tray of mixed devices sold as one unit is therefore both a logistics kit and, potentially, a regulated convenience kit.
How kitting works in practice
The logistics side is simple: a warehouse or vendor collects the components, packs them together and ships one unit. The device side adds an assembler who has to be able to support a determination. According to the FDA guidance:
- Components should be purchased in finished form, packaged and labelled consistently with their legal marketing authorization.
- The assembler or manufacturer decides whether any further processing of the kit, such as terminal sterilization, significantly affects the safety or effectiveness of any component. FDA says that responsibility rests with each assembler.
- Labeling for these kits “tends to be rather basic”, identifying the assembler or manufacturer and the intended use.
- Documentation supporting these determinations is kept in the assembler’s files under the Quality System regulation (21 CFR 820) and should be available to FDA.
The guidance names terminal sterilization as typical additional processing for these kits, and gives surgical sutures as an example of a component that may be sensitive to further processing.
Types or related concepts
Because the two meanings overlap, it helps to separate what each covers. The table sets the two meanings side by side.
| Question | Logistics kitting | FDA convenience kit |
|---|---|---|
| What is combined? | Components, parts or tools | Two or more different medical devices (21 CFR 801.3) |
| What is the purpose? | Prepare units ahead of production or shipment | Convenience of the purchaser or user |
| Who decides on further processing? | Not addressed by the glossary definition | The kit assembler or manufacturer |
| What records apply? | Not addressed by the glossary definition | Supporting documentation kept under 21 CFR 820, available to FDA |
FDA’s guidance also attaches a list of generic kit types organized by medical specialty, such as anesthesia kits, with “kit”, “set” and “tray” treated as the same thing. For examples of how named kits are described and classified, see the CASRAI guides on surgical packs and custom procedure trays.
Where it matters for labs, clinics and supply decisions
The enforcement-discretion checklist
FDA said it intends to exercise enforcement discretion, meaning it would not require 510(k) clearance for the kit itself, when all three of the following hold:
- The kit is of a type matching one on the attached list in the guidance.
- Its components have been cleared through the 510(k) process (the guidance also allows preamendments devices and devices exempt from premarket notification).
- The assembler can reasonably conclude that any further processing does not significantly affect the safety or effectiveness of any component.
This is a regulator’s enforcement position, not an exemption written into regulation: the guidance says FDA intends to propose rulemaking to formally exempt these kits. Assemblers also remain subject to other general controls, which the guidance names as registration, listing, the prohibition against misbranding and good manufacturing practices.
Scope limits stated by FDA
The guidance does not change drug requirements for kits that contain drug components, and it states it is not intended to apply to kit 510(k)s under the jurisdiction of the Center for Biologics Evaluation and Research.
Who holds the responsibility
Since the guidance places the processing determination and its documentation on the assembler, a kit’s labeling that identifies the assembler or manufacturer shows who holds that responsibility. Whether to assemble kits in-house or buy them pre-assembled is a separate decision, covered in pre-assembled procedure kits vs. building your own. For kitting applied to study supplies, see specimen collection kit standardization for multi-site trials, and for a worked example of a named kit see the PEG kit guide.
Common misunderstandings
- A kit is just a bundle, so no one is responsible for it. In the FDA guidance the assembler or manufacturer is responsible for considering how processing affects each component and for keeping the supporting documentation.
- Enforcement discretion means exempt. The guidance describes a policy of not requiring 510(k) clearance under stated conditions, and says FDA intended to propose rulemaking to formally exempt these kits.
- Any bundle of products is a convenience kit. The regulatory definition concerns two or more different medical devices. A bundle of non-device items is kitting in the logistics sense only.
- Kit, set and tray are different regulatory categories. For the purposes of the FDA guidance they are treated as synonymous.
FAQ
What does kitting mean?
Light assembly and preparation of components, parts or tools into one unit ahead of production or shipment (Penske Logistics glossary).
What is a convenience kit under FDA rules?
Under 21 CFR 801.3, two or more different medical devices packaged together for the convenience of the user.
Who is responsible when devices are kitted together?
Per the 1997 FDA guidance, the kit assembler or manufacturer must consider how any processing affects the components and keep supporting documentation under 21 CFR 820.
Sources
- FDA, Convenience Kits Interim Regulatory Guidance, May 1997 (docket FDA-2020-D-0957). Checked 2026-11-03.
- 21 CFR 801.3, definitions, via Cornell Legal Information Institute. Checked 2026-11-03.
- Penske Logistics, What is kitting? (logistics glossary). Checked 2026-11-03.
