Thailand Medical Device Classification: AMDD Classes 1-4
Classification is the first analytical step in any Thailand device registration strategy, and the first point where foreign manufacturers go wrong. Thailand uses a four-class, risk-based system aligned with the ASEAN Medical Device Directive (AMDD). US FDA risk categories and EU MDR classes do not map directly to Thai AMDD criteria, and a device classified by analogy to its home-market class is frequently wrong, which gets an application rejected at screening.
Last reviewed: July 2026
Why classification determines everything downstream
Under the Medical Device Act B.E. 2551 (2008) as amended by B.E. 2562 (2019), device class determines the registration pathway, the fee structure, the documentation package, and whether ISO 13485 certification is mandatory. None of these downstream decisions can be made correctly until the class is confirmed against Thai AMDD criteria.
The Medical Devices Control Division (MDCD) screens applications for classification accuracy before advancing them to review. An application filed under the wrong class is not rerouted; it is rejected, the fee is not refunded, and the timeline restarts from the beginning under the correct class.
Classification is not a judgment call a foreign manufacturer makes at its own discretion. It is a determination made against defined AMDD criteria, applied to the device as it will actually be used in Thailand, and when that intended use differs from the home-market registration, the Thai classification can differ too.
The AMDD classification criteria
Thailand's classification rules follow the ASEAN Medical Device Directive. The MDCD applies four primary criteria, each assessed against the device's stated intended use, not the device as a physical object in isolation.
Invasiveness
Whether the device enters the body through an orifice or through the body surface, and to what extent. Non-invasive devices are generally lower class; surgically invasive devices that penetrate the skin or body wall are generally higher class.
Duration of body contact
Transient contact (under 60 minutes), short-term contact (60 minutes to 30 days), and long-term contact (over 30 days) are defined categories. Extended contact duration increases risk classification, even within the same invasiveness category.
Intended use
The clinical function the device is labeled and designed to perform. A device intended to support a life-sustaining function is generally Class 4. Thai FDA classifies based on the manufacturer's own labeling and documentation, not what might be inferred from the device's physical design. This determination gets genuinely contested at the product boundary, as with dermal fillers, where composition and claimed function decide whether Thai FDA regulates the product as a drug or a device.
Active vs. non-active status
An active device relies on an external energy source other than gravity or energy generated by the human body. Active devices that administer or exchange energy with the patient are generally higher class; active implantables are among the highest-risk AMDD categories. Software-based devices are classified by their intended clinical function and the consequence of failure.
What Are the 4 Medical Device Classes in Thailand?
Each class has a defined pathway, a confirmed fee structure, and specific certification requirements. Every application pays an application fee and a certificate fee; on top of that, Thai FDA charges a separate specialist review fee case by case, when it determines a device needs deeper technical evaluation, typically due to newer or less-established technology. That determination becomes more common at higher risk classes: Class 1 essentially never triggers it, Class 2 sometimes does, Class 3 most often does, and Class 4 nearly always does. Fees below are set under the MoPH Ministerial Notification on Official Fees for Medical Devices, published September 19, B.E. 2567 (2024), confirmed current as of 2024 to 2026 and denominated in Thai Baht (THB).
Class 1 — Low risk: Listing
Total import fee: 3,100 THB, no expert review fee. ISO 13485 is not required; Thai GMP guidelines apply instead. Required documents: device description, Letter of Authorization, and conditional sterilization or calibration reports where applicable. Covers non-invasive devices with minimal patient contact risk, such as bandages, examination gloves, and basic non-energized diagnostic instruments.
Class 2 — Low-to-moderate risk: Notification
Base import fee: 11,000 THB (1,000 application, 10,000 certificate). If Thai FDA determines the device needs specialist review, an additional 38,000 THB applies, bringing the total to 49,000 THB; at Class 2 this review is not automatic and depends on the specific device. ISO 13485 certification and a full CSDT dossier are mandatory. Covers devices such as contact lenses, non-invasive diagnostic imaging equipment, and limited-invasiveness surgical instruments.
Class 3 — Moderate-to-high risk: Notification
Base import fee: 11,000 THB, same structure as Class 2. Specialist review applies to most Class 3 devices given the elevated risk profile, adding 38,000 THB for a typical total of 49,000 THB, though it is still determined case by case rather than automatic. ISO 13485 and a full CSDT dossier are mandatory, with a heavier documentation burden reflecting the elevated risk profile. Covers devices such as orthopedic implants, long-term implantables not in direct cardiovascular contact, and active therapeutic devices.
Class 4 — High risk: Full License
Base import fee: 21,000 THB (1,000 application, 20,000 certificate). Specialist review applies to nearly all Class 4 devices given the clinical stakes involved, adding 53,000 THB for a typical total of 74,000 THB. ISO 13485 is mandatory. The most demanding pathway in terms of documentation, clinical evidence, and expert review, covering cardiac valves, active implantables, and devices in direct contact with the central cardiovascular or nervous system.
Mapping AMDD Letter Classes (A–D) to Thai Numerical Classes (1–4)
The AMDD uses letter-based classes (A, B, C, D) across ASEAN member states; Thailand uses numerical equivalents (1, 2, 3, 4). The risk structures are equivalent, and manufacturers with existing ASEAN registrations will encounter both conventions.
AMDD Class A = Thai Class 1
Low risk. Listing pathway in Thailand.
AMDD Class B = Thai Class 2
Low-to-moderate risk. Notification pathway in Thailand.
AMDD Class C = Thai Class 3
Moderate-to-high risk. Notification pathway in Thailand.
AMDD Class D = Thai Class 4
High risk. Full license pathway in Thailand.
This equivalence applies within the ASEAN harmonization framework only. FDA risk categories (Class I, II, III under 21 CFR) and EU MDR classes (Class I, IIa, IIb, III) use different criteria and do not map directly to AMDD classes. A device classified as FDA Class II or EU MDR Class IIb can land in Thai Class 3 or Class 4 under AMDD criteria, depending on intended use and invasiveness. Classification by analogy to FDA or EU MDR class is a common source of misclassification in Thai submissions.
ISO 13485 requirements by class
ISO 13485:2016 certification is mandatory for Class 2, 3, and 4 submissions and is not required for Class 1 listing devices, which follow Thai GMP guidelines instead. Thai FDA publishes ISO 13485 guidance under the MDCD.
The certificate must be current at submission and remain current throughout the review period; an expired or suspended certificate stops a Class 2, 3, or 4 application from advancing. ISO 13485 certification covers the manufacturer's quality management system, it does not substitute for product-specific clinical evidence, risk management documentation, or CSDT format compliance.
