Why Mexico Has No Class IV Medical Device Category

1. Key takeaways

Mexico has no Class IV. RIS Articles 83 and 83 Bis establish only three classes — Class I, Class II and Class III — and the highest class is Class III. Importing the Class IV or Class D concept from other markets directly into a Mexican classification argument produces errors in two places at once: the classification rationale, because no statutory basis supports a fourth class, and the fee schedule, because official fees are set by class under the Mexican system and no tier exists for the imported label. This matters most for companies running multi-market programs, where a device may legitimately be Class IV in one jurisdiction and must nevertheless be mapped onto the Mexican three-class scheme. The mapping exercise is not mechanical — it requires applying the Mexican criteria of novelty and dwell time to the product as used — but it is straightforward once everyone accepts that the Mexican ceiling is Class III. Project documents, dossiers and internal tracking sheets should be scrubbed of Class IV references for Mexico before filing.

2. Legal basis

The table below compares the Mexican scheme with representative markets, to show where the four-class reflex comes from and why it does not transfer.

The comparison shows that the Mexican three-class structure is shared with the United States and China, while the four-class reflex typically comes from Canadian or ASEAN-style schemes. Neither resemblance makes the schemes interchangeable, as the insights below explain.

The comparison also has an administrative dimension. Every downstream artifact of a registration project inherits the class: the fee calculation, the dossier depth, the review expectations and even the language used in correspondence with the registration holder. If a Class IV label survives into any of those artifacts, the inconsistency surfaces later at the worst possible time — during review or at import. A short internal convention, such as requiring all Mexico-facing documents to state the class as a Roman numeral I, II or III with the Mexican legal basis beside it, is usually enough to keep the schemes apart in daily work.

3. Expert insights

Insight 1: Two three-class systems can still reach different answers. The United States and Mexico both use three classes, but the United States classifies through the product code and classification regulation number in the device classification database, while Mexico classifies through the principles of RIS Articles 83 and 83 Bis plus the 23 rules of the FEUM supplement. A US conclusion cannot simply be copied across the border. The criteria, the evidence expected and even the questions asked differ, so a device holding a given class in the United States may land in a different class in Mexico once the Mexican tests of novelty and dwell time are applied to it.

Insight 2: A Canadian Class IV device lands in Class III in Mexico. Schedule 1 of the Canadian regulations assigns devices that contact the central circulatory system or are used on the fetus to Class IV; in Mexico, such products are assessed against criteria such as novelty or residence in the body for more than 30 days, and most of them fall into Class III. The practical takeaway is that the highest-risk products in a portfolio remain fully covered by the Mexican system even though the top label is different. Teams translating Canadian dossiers for Mexico should re-run the Mexican criteria rather than carrying the Class IV designation into any Mexican-facing document.

Insight 3: IVDs in Mexico do not get a separate A to D scale. Diagnostic agents are one of the eight categories under LGS Article 262, and their risk classes are still determined within the three-class system. Some markets assign IVDs a dedicated A to D scale; Mexico does not follow that approach. A reagent that is Class D elsewhere must still be placed in Class I, II or III here, using the general criteria and the supplement rules. Assuming the A to D letter transfers leads directly to a classification that has no legal footing in Mexico.

Insight 4: The number of classes affects the evidence depth of the simplified pathway. The simplified pathway is not limited by class, but the depth of documentation escalates with the class, and Class III carries the heaviest evidence burden. Using the wrong class therefore undermines dossier depth in both directions: too low a class produces a file that is too thin for the review actually applied, and too high a class wastes preparation effort. Aligning the class early keeps the simplified pathway application on track.

4. Practical recommendations

1. For multi-market submissions, produce a separate classification rationale for each market instead of copy-pasting one argument across jurisdictions.
2. Keep the target-market class and the reference-country class in separate columns of the tracking ledger to prevent silent cross-contamination of conclusions.
3. In simplified pathway applications, treat the class stated on the reference-country approval as indicative only; the Mexican determination is what governs.
4. Prepare evidence for implantable and life-supporting products at Class III depth, and reserve capacity for the clinical evaluation materials that this depth requires.

5. Verification checklist

• □ Confirmed that the highest class in Mexico is Class III
• □ No Class IV or Class D concept imported from other markets
• □ Classification rationale issued independently for each market
• □ No A to D scale applied to IVDs
• □ Class in the simplified pathway application re-verified under the Mexican approach

Regulatory information verified as of October 28, 2026.

How GRZAN can help. GRZAN provides medical device and IVD registration, quality system, authorised representative and local testing support for the Mexican market. Our team manages COFEPRIS registrations and equivalence (equivalencia) reviews, coordinates third-party authorised centre routes, and supports post-market vigilance obligations. Business enquiries: info@grzanglobal.com