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JMDN — Japan Medical Device Nomenclature

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 device must be assigned a JMDN code before an application can be filed. The JMDN code determines the device class, applicable recognised standards, and the regulatory pathway. There is no direct equivalent in the EU MDR, FDA, or TGA systems (the closest analogy is the FDA Product Code, but JMDN is more prescriptive about pathway implications).

What JMDN is​

JMDN is a hierarchical nomenclature system administered by MHLW. Each distinct device type is assigned a numeric JMDN code (typically 7 digits) along with:

  • A Japanese device type name
  • The assigned risk class (I–IV)
  • The applicable Ministerial Ordinance category
  • Applicable recognised standards (for Ninsho eligibility)

JMDN codes are used in every regulatory submission — from pre-market applications to adverse event reports and post-market surveillance submissions.

Structure of JMDN codes​

JMDN codes are grouped into broad categories (e.g. cardiovascular devices, orthopaedic devices, IVDs). Within each category, devices are further subdivided by type, material, and intended use. Each JMDN code is hierarchical: a 7-digit code structure allows for specificity at the device-type level.

For example, a cardiac pacemaker would have a specific JMDN code (Class IV) that pre-assigns it to the Shonin pathway with no Ninsho option available; conversely, a hearing aid (Class II) would have a different JMDN code indicating Ninsho eligibility if a recognised standard applies.

How to find the correct JMDN code​

  1. MHLW JMDN database — MHLW publishes a searchable database of JMDN codes. Search by device type description, material, or intended use (Japanese language required for the database)
  2. PMDA consultation — for novel devices or borderline types, PMDA can advise on appropriate JMDN code assignment
  3. Existing approvals — checking the JMDN code used in existing PMDA-published approval summaries for similar devices
  4. Specialist regulatory consultants — Japan-based RA consultants with JMDN experience

JMDN and GMDN — relationship and differences​

The Global Medical Device Nomenclature (GMDN) is an international system used by many countries including the EU and Australia. JMDN and GMDN serve similar functions but are separate systems:

  • JMDN is Japan-specific and legally required for Japanese applications
  • GMDN codes and JMDN codes often do not map 1:1 — a single GMDN category may correspond to multiple JMDN codes
  • MHLW has worked to increase alignment between JMDN and GMDN, but the systems remain distinct

Creating new JMDN codes​

If no existing JMDN code covers a genuinely novel device type, the MAH must request MHLW to create a new code. This process can take 6–12+ months and must be completed before a formal application can be filed — a device without an assigned JMDN code cannot enter pre-market review. The request should be initiated early in the development/regulatory strategy process, often in parallel with or before PMDA pre-submission consultation. A new JMDN code assignment also requires MHLW to designate the risk class (I–IV) and determine pathway eligibility, which frequently involves engagement with PMDA to assess intended use and risk profile.

It is strongly advisable to confirm the JMDN code with a Japan-based regulatory consultant or through PMDA pre-submission consultation before formally filing an application, as an incorrect code assignment will delay the application process, may result in rejection, and will require substantial resubmission effort.