Post-Market Change Management and the IDATEN Procedure

1. Key takeaways

Post-market changes in Japan are handled in three tiers: notification of minor changes, partial-change approval, and a pre-confirmation under the change-plan confirmation procedure (IDATEN) of whether a notification can suffice. The critical difference among the tiers is not speed but whether re-examination is required. GRZAN recommends that software products with frequent iteration prioritize the use of IDATEN, so that the question of whether a notification alone is possible is settled before the change is made. Whether a change requires re-examination determines the entire downstream workload — the study data needed, the review timeline, and the approval risk — so the tier determination is the most consequential judgment in the whole change process. Getting the tier right at the start is therefore worth more than any later acceleration of the procedure itself.

• Minor changes that do not affect efficacy or safety are handled by notification.
• Changes to approved matters require partial-change approval, which means re-examination of the affected matters.
• IDATEN allows a pre-change confirmation of whether notification alone is possible.
• Manufacturing-site changes follow a fixed order: foreign manufacturer registration first, then the item-level change. Keeping all four points in one internal rule prevents each change from being classified afresh by whichever team happens to handle it.

2. Legal basis

The three-tier structure and the supporting procedures rest on the following provisions of the current framework (Act No. 145 of 1960) and PMDA guidance. Because the 2025 amendment moved several item numbers, every citation must be checked against the current text on e-Gov before use. The tier itself never changes by administrative convenience: the classification follows the substance of the change, and the procedure follows the classification.

1. PMD Act Article 23-2-5: approval of partial changes to approved matters and notification of minor changes (caution: the relevant item numbers were moved by Act No. 37 of 2025, promulgated May 21, 2025; confirm against the current text on e-Gov when citing).
2. Change-plan confirmation procedure (the IDATEN system): under the relevant PMD Act provisions, a pre-confirmation of whether a change made under a change plan can be handled by notification; in force since September 1, 2020 (Reiwa 2).
3. PMD Act Article 23-2-4, paragraph 1: registration of foreign manufacturers — a change of manufacturing site requires the registration to be updated first.
4. PMD Act Article 23-2-5, paragraph 7: QMS conformity investigation before partial-change approval (in cases such as addition of facilities or a change of sterilization method).
5. PMDA public material: review points issued for raw-material change procedures and similar matters (practical estimate: the specific notification numbers and dates are as published by PMDA for the time being).
6. Current legal framework: Act No. 145 of 1960.

3. Expert insights

Insight 1: the boundary between a minor change and a partial change is whether efficacy or safety is affected. A minor change is a change that does not affect efficacy or safety and is handled by notification; changes to other approved matters require partial-change approval. Companies tend to underestimate the impact of a change at the judgment stage, particularly for software, where a small code-level difference can still alter clinical behavior. GRZAN’s approach is a change-impact assessment table that scores the change item by item across the three dimensions of efficacy, safety and performance. Documenting the assessment also creates the record that supports the chosen tier if the classification is questioned later.

Insight 2: IDATEN turns the question of whether notification suffices into a matter that can be confirmed in advance. IDATEN allows, before a change is made, a confirmation of whether a change carried out under a change plan can be handled by notification. This is most valuable for software devices that require continuous iteration, because it moves the uncertainty from being told after submission that the approval route must be used, to holding written confirmation before submission. For a product updated several times a year, the cumulative value of holding such confirmations is substantial, since each iteration otherwise carries its own risk of reclassification after the fact. The confirmation also disciplines internal planning: once the route is fixed in writing, the development team can build to it rather than around it.

Insight 3: manufacturing-site changes follow a fixed order. Adding or replacing a manufacturing site requires the foreign manufacturer registration to be updated first, before the item-level change is pursued. Reversing the order causes the item change application to fail because the manufacturing site is not registered — a procedural error that is entirely avoidable. The registration step and the item-level change are handled through different procedures, and only the correct order allows both to proceed without rework. Planning the two steps on one timeline, with the registration milestone first, removes the sequencing risk altogether.

4. Practical recommendations

• Build a change-impact assessment table. Assess across efficacy, safety and performance, and output a conclusion on which tier applies, so that the classification decision rests on a documented analysis rather than on individual judgment.
• Prioritize IDATEN for frequently iterated products. Obtain written confirmation of whether notification is possible before the change is implemented, and file the confirmation with the change record so the basis for the chosen route is always retrievable.
• Execute manufacturing-site changes strictly in the order of registration first, change second.
• Schedule the QMS investigation in parallel for facility additions or sterilization-method changes. These are triggering situations for the investigation that precedes partial-change approval, so the investigation scheduling belongs inside the change plan itself rather than beside it.

5. Verification checklist

• □ Has a change-impact assessment table been built (efficacy, safety and performance dimensions)?
• □ Is the use of IDATEN planned for frequently iterated products (in force September 1, 2020)?
• □ Are manufacturing-site changes executed as foreign manufacturer registration first, item change second?
• □ Is the QMS conformity investigation scheduled in parallel for facility additions or sterilization-method changes?
• □ Are the cited item numbers of Article 23-2-5 confirmed against the current text on e-Gov?

Regulatory information verified as of October 29, 2026.

How GRZAN can help. GRZAN provides medical device and IVD registration, quality system, in-country representative and local testing support for the Japanese market. Our team manages adverse event reporting and recall coordination with PMDA, and supports post-market vigilance obligations. Business enquiries: info@grzanglobal.com