Class 3 and 4 Item Approval in South Korea: MFDS Review Timelines and Fees

1. Key takeaways

Class 3 and Class 4 devices go through item approval, reviewed directly by the Ministry of Food and Drug Safety (MFDS) without passing through a designated review organization. The statutory review period is 55 working days without a clinical trial and 70 working days with one; the official fees are KRW 561,000 without a clinical trial and KRW 1,338,000 with one.

The two classes share the same review period and fee standard; the difference lies in review depth and documentation requirements. Class 4 is the highest risk class, with stricter requirements on the safety and effectiveness argumentation in the technical documents and on the completeness of clinical data. Whether a clinical trial is required is the only variable that changes the period and the fee: from 55 working days to 70 working days, and from KRW 561,000 to KRW 1,338,000.

GRZAN places the pacing control point of Class 3 and 4 projects on the coordination between the technical documents and the clinical data: the two are not sequential but mutually supporting, and whichever side finishes first may have to be reworked when the other side triggers a deficiency.

2. Legal basis

Approval of Class 3 and 4 devices rests on the following instruments.

Review periods and fees for Class 3 and Class 4 (per the Enforcement Rule annex)

3. Expert insights

The dividing line of the period is whether a clinical trial is needed, not the class. Class 3 and Class 4 sit in exactly the same period and fee band; the only trigger that moves a project from 55 working days to 70 working days is the need to submit clinical trial data. The first question in project scheduling is therefore not which class the product is, but whether a clinical trial is needed. GRZAN answers this question at the assessment stage and then works the documentation plan backwards from it; if the answer is yes, the performance specifications in the technical documents must stay consistent with the clinical trial’s evaluation endpoints, otherwise the two documents undermine each other.

Staged review is an available pacing tool. MFDS Public Notice No. 2022-52 provides a staged review arrangement. For Class 3 and 4 projects under schedule pressure, staged submission breaks long-running documentation work into deliverable segments instead of waiting until every document is complete. GRZAN notes that staged review changes the submission rhythm, not the statutory period basis of 55 or 70 working days; the two must not be mixed in scheduling.

The technical documents and the clinical data must share one specification baseline. The technical documents state the performance and test specifications; the clinical data verify clinical benefit and safety. If the performance claims in the technical documents do not correspond to the primary endpoints of the clinical protocol, the review will ask for supplementary explanations and the number of deficiency rounds grows. GRZAN treats a specification crosswalk table as a mandatory deliverable on Class 3 and 4 projects: performance items from the technical documents on the left, clinical evaluation endpoints on the right, matched line by line, so gaps are found before submission.

The difference between Class 3 and Class 4 lies in depth of argumentation, not procedure. Both are reviewed by MFDS with the same period and the same fees, but as the highest class, Class 4 faces stricter requirements on the risk-benefit argumentation and clinical evidence. GRZAN’s practical estimate is that Class 3 products on a substantial equivalence route can often keep the dossier compact, while Class 4 products are rarely argued entirely by comparison. This judgment is a practical estimate; at the statutory level there is no difference between the two classes in period or fees.

4. Practical recommendations

• Decide at the assessment stage whether a clinical trial is needed. The conclusion fixes both the period (55 or 70 working days) and the fee (KRW 561,000 or 1,338,000) and must be locked first.
• Build a specification crosswalk between the technical documents and the clinical data. Match performance items against clinical evaluation endpoints line by line and eliminate inconsistencies before submission.
• Run KGMP in parallel with document review. Classes 2-4 all require a KGMP certificate; running them in series stretches the project by months.
• Track deficiency rounds as the primary progress metric. The statutory period is not controllable, but first-pass document quality is; GRZAN manages Class 3 and 4 projects by deficiency rounds rather than by review days.
• Reserve more argumentation time for Class 4 products. The highest class faces stricter evidence requirements, so plan documentation preparation at a level above Class 3 (practical estimate).

5. Verification checklist

• □ Class confirmation — cross-check against Annex 1 of the Enforcement Rule; standard: clearly Class 3 or Class 4.
• □ Clinical trial necessity — judged from the product characteristics and existing evidence; standard: a definite conclusion, from which 55 or 70 working days is fixed.
• □ Receiving body — mapped by class; standard: Class 3 and Class 4 are both reviewed directly by MFDS.
• □ Specification alignment — crosswalk of technical document performance items and clinical endpoints built; standard: matched line by line with no gaps.
• □ Clinical trial plan approval — check applicability under Article 10 of the Medical Device Act; standard: products requiring a clinical trial have obtained approval.
• □ KGMP status — judged by class with the certificate validity checked; standard: a valid KGMP certificate held, valid for 3 years.
• □ Fee basis — check the Enforcement Rule annex; standard: consistent with the value tied to whether a clinical trial is required.

How GRZAN can help. GRZAN provides medical device and IVD registration, quality system, Korean licence holder and local testing support for the Republic of Korea. Our team manages MFDS approvals, certifications and notifications, prepares equivalence dossiers, and supports post-market vigilance obligations. Business enquiries: info@grzanglobal.com