NOMs Overview — Official Mexican Standards
Normas Oficiales Mexicanas (NOMs) are mandatory technical standards issued by Mexican government ministries. Unlike voluntary standards such as ISO norms (which are referenced but not legally binding unless adopted into a NOM), NOMs carry the full force of law.
What makes a NOM mandatory?
A NOM is issued under the authority of the Ley Federal sobre Metrología y Normalización (Federal Law on Metrology and Standardisation). Once published in the Diario Oficial de la Federación (DOF), compliance is compulsory for all relevant parties within the scope of the NOM — no matter where the product is manufactured.
NOM vs voluntary standards (NMX, ISO)
| Standard type | Acronym | Mandatory? | Who sets it |
|---|---|---|---|
| Official Mexican Standard | NOM | Yes — by law | Government ministries |
| Mexican Standard | NMX | No — voluntary | IMNC / industry bodies |
| International standard | ISO / IEC | No (unless incorporated into a NOM) | ISO / IEC |
Many international standards (ISO 13485, ISO 14971, ISO 10993) are widely used in Mexico and recognised by COFEPRIS — but compliance with them is achieved through their equivalency to NOM requirements, not because ISO standards are independently binding.
Key device-related NOMs
| NOM | Title | Status |
|---|---|---|
| NOM-241-SSA1-2025 | Good Manufacturing Practices for Medical Devices | In force — April 2025 |
| NOM-137-SSA1-2008 | Labelling of Medical Devices | In force (draft update 2024) |
| NOM-240-SSA1-2012 | Installation and Operation of Technovigilance | In force (draft update 2024) |
The NOM development process
- Draft NOM (PROY-NOM) — draft published in the DOF, open for public comment.
- Comment period — typically 60 days; stakeholders may submit observations.
- Finalisation — the issuing ministry reviews comments and publishes the final NOM in the DOF.
- Transition period — the final NOM usually includes a transition period before entry into force.
How to access NOMs
- Current NOM texts are available through the DOF (dof.gob.mx).
- The COFEPRIS website links to applicable device NOMs.
- The IMNC (Instituto Mexicano de Normalización y Certificación) maintains a catalogue.
Note that the official NOM texts are published in Spanish. English translations may be available from regulatory consultants but are not official.