Device Classification: Class I, Class II and Class III in the United States

1. Key takeaways

In the United States, medical devices are classified by risk into Class I, Class II, and Class III, with the intensity of regulatory controls increasing by class. Most Class I devices are exempt from 510(k), most Class II devices require a 510(k), and most Class III devices require a PMA. Classification is authorized by FD&C Act section 513, the specific classification rules are codified in 21 CFR Parts 862 through 892, and they are supported by the product classification database. Because the class determines the premarket pathway, the post-market burden, and the way listing records are grouped, classification is not a labeling exercise performed at the end of a project. It is a foundational determination that should be completed, documented, and verified before any submission work begins, and it should always be performed against the regulation and the database rather than against habit or the naming conventions used in other markets.

• The United States uses only three classes; it does not use the Class A/B/C/D system seen in some other jurisdictions.
• Class mapping between the United States and other markets must be built separately for each market; Class IIa is not Class II.
• The operative carrier of classification is the product code, not a self-declared category.
• Under 21 CFR 807.28(f), all devices under one exempt product code share a single listing number; non-exempt devices get one listing number per premarket submission number.
• Exemption from 510(k) removes only the premarket notification track, not registration, listing, QMSR, labeling, or MDR duties.

2. Legal basis

The following authorities govern classification and its consequences. The classification paragraphs in 21 CFR Parts 862 through 892 are the operative text: each device type paragraph states the class and the exemption status, and those statements control over any general description found in brochures, databases, or marketing materials.

3. Expert insights

Insight one: the United States has only three classes and does not adopt the A/B/C/D system.

The American system is Class I/II/III. It has no one-to-one correspondence with the Class A/B/C/D (or Class 1 through 4) frameworks used in parts of Southeast Asia, Latin America, and other regions. When GRZAN runs parallel submissions across multiple markets, a separate classification mapping must be built for each market, and Class IIa must never be treated as equivalent to Class II. Risk classes with similar names carry different evidence expectations, different conformity routes, and different post-market burdens, so a mapping that looks superficially reasonable can still misdirect the whole program. The safe practice is to record, for every market, the exact national class, the rule that assigns it, and the reason the mapping holds, so that a reviewer in any jurisdiction can follow the logic without guessing.

Insight two: the carrier of classification is the product code, not a category self-reported by the company.

Each device type has a corresponding classification regulation in 21 CFR 862 through 892 and is associated with a product code. That product code simultaneously determines the classification level, whether a 510(k) is required, and how the device is grouped at listing, either under an exempt product code or under a premarket submission number. Under 21 CFR 807.28(f), all devices under one exempt product code share a single listing number, while non-exempt devices are assigned one listing number for each premarket submission number. Because so many consequences flow from a single code, the code selection deserves its own review step, with the underlying regulation paragraph recorded in writing, rather than being folded silently into the listing form.

Insight three: most Class I devices are exempt from 510(k), but exemption waives only one track of obligations.

FDA’s official statement is that most Class I devices are exempt from Premarket Notification 510(k). However, the five obligations of establishment registration, device listing, QMSR, labeling, and MDR apply to exempt devices in exactly the same way as to cleared ones. This theme is developed further in article 05 of this series, which walks through the duties that survive exemption. The practical message for planning is straightforward: a 510(k) exemption reduces the premarket workload, but it does not create a lighter compliance regime, and teams that budget for exemption as if it were deregulation will find the remaining obligations arriving anyway.

4. Practical recommendations

• Base every classification determination on the product classification database together with the classification regulations in 21 CFR 862 through 892, and never on the company’s habitual naming or on names inherited from other markets.
• One device type may correspond to several product codes, for example where indications for use or technical characteristics differ, so confirm each code individually and record why each applies or does not.
• Where the determination lands in Class III and no predicate device exists, plan a De Novo or PMA pathway early, and do not prepare a 510(k) package that cannot be filed.
• For parallel submissions across markets, build a dedicated United States classification mapping table and note the basis for each mapping entry.

5. Verification checklist

• □ The product code has been determined, and its classification regulation number within 21 CFR 862-892 has been recorded.
• □ The 510(k) exemption status of that product code has been confirmed.
• □ Where a 510(k) is required, the availability of a citable predicate device has been confirmed.
• □ It has been confirmed that QMSR and labeling obligations apply to this classification as well.
• □ A classification mapping table between the United States and the other target markets has been established.

Regulatory information verified as of October 28, 2026.

How GRZAN can help. GRZAN provides medical device and IVD registration, quality system, US Agent and local testing support for the United States market. Our team manages FDA establishment registration and listing, 510(k)/De Novo/PMA submissions, and supports post-market reporting obligations. Business enquiries: info@grzanglobal.com