JMDN — Nomenclature and Device Codes

JP-unique

JMDN (Japan Medical Device Nomenclature / 日本医療機器命名制度) is Japan's official device classification and nomenclature system. Every medical device marketed in Japan must be assigned a JMDN code — a mandatory element in all pre-market applications, labels, and regulatory submissions.

What JMDN is

JMDN is a hierarchical system that assigns every type of medical device a unique numeric code and a defined Japanese name. The JMDN database is maintained by MHLW and covers:

• Device type name in Japanese
• Assigned risk class (I, II, III, or IV)
• Whether the device type is subject to a recognised standard (and therefore potentially Ninsho-eligible)
• Associated performance requirements or special requirements for the device type

Structure of JMDN codes

JMDN codes are typically 7-digit numeric codes (though older codes and some special categories may have different digit structures; users should verify the exact format of their assigned code in the MHLW database). The code structure places devices into broad category groupings, though the specific groupings are not directly derived from the code number alone — the database must be referenced.

Example groupings include:

• Cardiovascular devices (including stents, pacemakers, catheters)
• Orthopaedic devices (implants, bone screws, joint replacements)
• Ophthalmic devices (contact lenses, intraocular lenses)
• IVDs (separated from therapeutic devices with their own codes)
• Active devices (imaging, therapeutic energy)
• Software / Programme Medical Devices (specific JMDN codes created post-2014)

How JMDN determines regulatory pathway

The JMDN code directly determines:

1. Risk class — the class pre-assigned to that device type determines whether Shonin, Ninsho, or Todokede applies
2. Ninsho eligibility — whether a recognised standard exists for the code determines whether Ninsho is available
3. Post-market requirements — re-examination periods and GPSP intensity are set based on device class and JMDN category

Searching the JMDN database

For English-speaking users without Japanese proficiency: Engage a Japan regulatory consultant or translator to identify the Japanese device type name, then search the MHLW JMDN database

JMDN and GMDN — comparison

Feature	JMDN	GMDN
Administered by	MHLW (Japan)	GMDN Agency (global, UK-based)
Used in	Japan regulatory submissions, labels	EU, Australia, US (UDI), and others
Pre-assigned class	Yes — class is fixed in the JMDN database	No — classification is done separately in each country
Link to recognised standards	Yes — JMDN code links to applicable Japanese standards	No direct link to national standards
Language	Japanese	English
Mandatory in Japan	Yes	No (GMDN is not required for Japanese submissions)

Creating new JMDN codes

For genuinely novel device types with no existing JMDN code, the MAH must request MHLW to create a new code. The process:

1. MAH submits a written request to MHLW with device description, intended use, and proposed classification
2. MHLW (with PMDA input for higher-risk devices) evaluates the request and assigns a class
3. MHLW creates the new JMDN code and publishes it
4. Timeline: typically 6–18 months depending on novelty and MHLW workload

New JMDN code creation is a critical path item for novel devices — begin early.

Example: a Class III cardiovascular stent might be coded as 2670024 (where the first digit or digit group indicates the major category, and subsequent digits further subdivide the device type). The exact hierarchical meaning of each digit position is not publicly documented; only the final assigned code matters for regulatory purposes.

Reclassification of existing devices: If a device differs substantially from the existing JMDN code definition but does not qualify as entirely new, an MAH may request reclassification or request assignment to a different existing code. Submit a request to MHLW with supporting evidence of material differences in intended use, design, or risk profile. Timeline is typically 3–12 months.