How the USML Is Organized
The USML is not a catalog of specific part numbers — it is a functional list. Each of the 21 categories describes a class of defense articles by capability and design intent, and within each category, lettered paragraphs (a), (b), (c), and so on enumerate controlled items at increasing specificity. Reading the USML correctly requires understanding three structural conventions:
- End-items first, then parts. Most categories begin with complete systems (an aircraft, a vessel, a missile) and follow with paragraphs capturing components, parts, accessories, attachments, and associated equipment "specially designed" for those systems.
- Technical data and defense services ride along. Nearly every category includes a paragraph controlling the technical data (blueprints, specifications, source code) and defense services directly related to the articles in that category. You do not need to ship hardware to violate ITAR — emailing a controlled drawing to a foreign person is an export.
- Significant Military Equipment (SME) designations. Items marked with an asterisk on the USML are Significant Military Equipment, warranting stricter controls: exports require a non-transfer and use certificate (DSP-83), and licensing scrutiny is elevated.
The phrase that decides most real-world classification questions is "specially designed", defined at 22 CFR 120.41. An item is specially designed if, as a result of development, it has properties peculiarly responsible for achieving or exceeding controlled performance levels or functions — but the definition also contains "release" provisions that exclude, for example, items with the same function and equivalent performance as items in normal commercial use. Applying this definition correctly is the difference between a lawful commercial sale and an unauthorized export of a defense article. For the broader regulatory context — who must register, what ITAR controls, and how the pieces fit together — start with our definitive guide to ITAR.
Categories I–V: Weapons, Ordnance & Energetic Materials
Category I — Firearms and Related Articles
Covers firearms retained under ITAR control — including fully automatic firearms, weapons specially designed for military application, and their specially designed parts, components, and accessories — along with related technical data. Note the jurisdictional history: in March 2020, many non-automatic and semi-automatic firearms of a commercial character transitioned from the USML to the Commerce Control List, so a firearms product line today may straddle both ITAR and EAR jurisdiction. Firearms manufacturers, importers of military small arms, and suppliers of fire-control components should classify at the model-and-variant level, not the product-family level.
Category II — Guns and Armament
Controls large-caliber military weapons: howitzers, mortars, cannons, recoilless rifles, and similar armament, together with their mounts, breech mechanisms, and specially designed components. Practical examples include artillery tubes, gun turret assemblies, and autoloader mechanisms. Affected industries include heavy manufacturing, precision forging and machining shops supplying artillery programs, and naval gun system integrators.
Category III — Ammunition and Ordnance
Covers ammunition for the weapons in Categories I and II, plus specially designed components: projectiles, cartridge cases, fuzes, primers designed for military ammunition, and ammunition manufacturing equipment. A commercial brass supplier producing cartridge cases to a military specification can find itself manufacturing a defense article. As with Category I, certain sporting ammunition moved to EAR control in 2020 — jurisdiction depends on the specific item.
Category IV — Launch Vehicles, Guided Missiles, Ballistic Missiles, Rockets, Torpedoes, Bombs, and Mines
One of the most sensitive categories, covering missiles and rockets of every class, torpedoes, bombs, mines, and their launch and guidance systems — plus specially designed parts. Practical examples: rocket motor cases, missile seeker assemblies, torpedo propulsion sections, and flight termination systems. This category touches aerospace primes, propulsion suppliers, and — increasingly — commercial space companies whose launch vehicle work overlaps missile technology.
Category V — Explosives and Energetic Materials, Propellants, Incendiary Agents, and Their Constituents
Controls military explosives (such as RDX and HMX), propellants, oxidizers, incendiary agents, and specified precursor chemicals, along with production technology. Specialty chemical manufacturers are the classic affected industry — a company that considers itself a chemicals business, not a defense business, may nonetheless be producing USML-listed energetic materials requiring DDTC registration.
Categories VI–X: Military Platforms & Personnel Equipment
Category VI — Surface Vessels of War and Special Naval Equipment
Covers warships and other combatant vessels, mine countermeasure vessels, and specially designed naval equipment and components. Examples include naval combat system consoles, shipboard weapons-handling equipment, and hull sections built to combatant specifications. Shipyards, marine equipment suppliers, and naval electronics integrators are the primary affected industries.
Category VII — Ground Vehicles
Controls tanks, armored personnel carriers, combat engineering vehicles, and other ground vehicles specially designed for military use, plus armor packages and specially designed components. Practical examples: armored hull weldments, active protection system components, and military-unique drivetrain assemblies. Commercial truck platforms modified with armor or weapons integration can cross into Category VII, which surprises vehicle upfitters entering the defense market.
Category VIII — Aircraft and Related Articles
Covers military aircraft — fighters, bombers, attack helicopters, and unmanned aerial vehicles specially designed for military use — and specified components. Under Export Control Reform, many less-sensitive aircraft parts moved to the CCL's 600 series (notably ECCN 9A610), so aerospace suppliers routinely manage split USML/EAR classifications across a single bill of materials. Machine shops, avionics suppliers, and MRO providers serving defense aviation are heavily affected.
Category IX — Military Training Equipment and Training
Controls simulators and training equipment specially designed for military use — flight simulators for combat aircraft, weapons system trainers, radar target generators — and the associated training services. Simulation software firms and training system integrators should note that furnishing military training to foreign persons is a defense service requiring DDTC authorization even when no hardware changes hands.
Category X — Personal Protective Equipment
Covers body armor and helmets providing protection levels specified in the category text, protective clothing designed for military application (including certain chemical/biological protective gear), and specially designed components such as ballistic plates and inserts. Body armor manufacturers selling internationally must classify carefully — protection level and design intent determine whether an item is ITAR-controlled or EAR-controlled.
Categories XI–XV: Electronics, Sensors, Materials & Space
Category XI — Military Electronics
One of the broadest and most frequently implicated categories: military radar, electronic warfare systems, military communication and command-and-control electronics, underwater acoustic systems, and specially designed electronic assemblies and components. RF/microwave component makers, PCB assemblers, and embedded systems developers serving defense programs live in Category XI — and its technical data paragraph makes engineering collaboration with foreign persons a recurring deemed export risk.
Category XII — Fire Control, Laser, Imaging, and Guidance Equipment
Controls fire control systems, military rangefinders, laser targeting and designation equipment, night vision and image intensification equipment, infrared focal plane arrays meeting category criteria, and inertial navigation and guidance systems for defense articles. Electro-optics companies are the core affected industry; image intensifier tubes and military-grade IR sensors are classic Category XII articles that show up in supply chains far from any obvious "weapon."
Category XIII — Materials and Miscellaneous Articles
A diverse category covering, among other things, military cryptographic and information security equipment specified in the category, armor materials meeting military specifications, signature-reduction (stealth) materials and coatings, and certain ablative and structural materials. Advanced materials companies — composites, ceramics, specialty coatings — should screen against Category XIII whenever a material is developed to a defense specification.
Category XIV — Toxicological Agents, Including Chemical Agents, Biological Agents, and Associated Equipment
Controls chemical warfare agents, biological agents adapted for warfare, riot control agents specified in the category, and the detection, protection, and decontamination equipment specially designed for military use against them. Affected organizations include biodefense contractors, detection instrument manufacturers, and research institutions working under defense biodefense programs.
Category XV — Spacecraft and Related Articles
Covers spacecraft and satellites with military or intelligence capabilities described in the category, anti-satellite systems, specified spacecraft components, and ground control equipment. Export Control Reform moved many commercial communications and remote sensing satellites to the EAR, but satellites and components meeting Category XV's performance criteria remain ITAR-controlled — and the September 2025 revisions updated this category to reflect commercial space industry growth. NewSpace startups should never assume "commercial" means "EAR": classification turns on the category text, not the business model.
Categories XVI–XXI: Special Categories & the Catch-All
Category XVI — Nuclear Weapons Related Articles
Controls articles, technical data, and services related to nuclear weapons employment and testing that fall under ITAR rather than the Department of Energy or Nuclear Regulatory Commission regimes. This is a narrow category in practice — most nuclear technology is controlled under separate statutory authorities — but modeling and simulation tools for nuclear weapons effects are a real-world example.
Category XVII — Classified Articles, Technical Data, and Defense Services Not Otherwise Enumerated
Captures any classified article, technical data, or defense service that is not enumerated elsewhere on the USML. If information or hardware is classified and defense-related, it is ITAR-controlled regardless of whether another category describes it. Cleared contractors handling classified programs should treat this as a floor beneath every other classification decision.
Category XVIII — Directed Energy Weapons
Controls directed energy weapon systems — high-energy lasers, high-power microwave and radiofrequency weapons, particle beam systems — and their specially designed components and test equipment. Once exotic, this category increasingly matters to photonics and high-power RF companies whose components feed counter-drone and ship-defense laser programs.
Category XIX — Gas Turbine Engines and Associated Equipment
Covers gas turbine engines specially designed for defense articles (military aircraft, ground vehicles, and vessels), hot-section components, digital engine controls meeting category criteria, and related production technology. Turbine blade and vane manufacturers, casting houses, and engine MRO shops are the affected industries — hot-section technology is among the most tightly protected data in the aerospace supply chain.
Category XX — Submersible Vessels and Related Articles
Controls submarines and other submersible vessels designed for military use, naval nuclear propulsion plants and their specially designed components, and related equipment. Beyond submarine primes, this category reaches suppliers of acoustic quieting technology, pressure-hull materials, and unmanned undersea vehicles designed for military missions.
Category XXI — Articles, Technical Data, and Defense Services Not Otherwise Enumerated
The catch-all. Category XXI captures items with substantial military applicability that were developed or funded for military purposes but are not described in Categories I–XX — and an item lands here only by formal DDTC determination, not by self-designation. Its practical significance: the USML's enumerated categories are not the outer boundary of ITAR. If you have developed something genuinely novel for a defense application, do not assume the absence of a matching paragraph means the absence of control — seek a determination.
How to Determine If Your Product Is on the USML
Classification is a disciplined, documented process — not a gut call. The methodology we use across 200+ client engagements follows the regulatory order of review:
- Start with the USML (22 CFR 121.1). U.S. export jurisdiction analysis begins with ITAR. Identify every USML category plausibly relevant to your item's function, and read each paragraph — including the notes — against your item's actual specifications and design history.
- Apply the "specially designed" analysis (22 CFR 120.41). For parts and components, work through the definition's "catch" provisions and then each "release" provision in order. Document which paragraph catches the item, or which release lets it out. Design history matters: an item developed on a defense contract is analyzed differently than a commercial catalog item later purchased for a military program.
- If not USML-controlled, review the CCL. Items not described on the USML fall under EAR jurisdiction. Check the 600-series ECCNs first (former USML items), then the rest of the Commerce Control List, before concluding an item is EAR99.
- Write it down. A defensible classification includes the item's identity and specifications, the category and paragraph analysis, the specially-designed reasoning, the conclusion, the date, and the reviewer. Undocumented classifications are worth little in an enforcement proceeding — and classifications made before September 2025 need re-validation against the revised category text.
- Escalate genuine ambiguity to DDTC. When the analysis cannot resolve jurisdiction with confidence, a Commodity Jurisdiction request (below) is the legally safe path.
Two classification errors dominate the violations we see in practice. First, companies classify at the product-family level when the USML demands item-level analysis — one variant of a sensor may be ITAR-controlled while its sibling is EAR-controlled. Second, companies treat "we bought it commercially" as proof of EAR status, when the question is what the item was designed for, not where it was purchased. Misclassification is not a paperwork problem: every unauthorized export that flows from a wrong classification is a separate violation. See our full breakdown of ITAR violations and penalties for what that exposure looks like.
The USML, the CCL, and the 600 Series
The USML does not exist in isolation. Under Export Control Reform (ECR), the U.S. government moved thousands of less-sensitive military items from the USML to the Commerce Control List, creating the "600 series" — ECCNs whose third character is a 6 (for example, 9A610 for certain military aircraft parts). Understanding the relationship prevents two costly mistakes: treating a 600-series item as uncontrolled, and treating it as ITAR-controlled when Commerce licensing rules actually apply.
| Attribute | USML (ITAR) | CCL 600 Series (EAR) |
|---|---|---|
| Regulator | State Department (DDTC) | Commerce Department (BIS) |
| What it lists | Defense articles, services & technical data (22 CFR 121.1) | Less-sensitive military items moved off the USML under ECR |
| Registration | Mandatory DDTC registration for manufacturers & exporters | No registration requirement |
| Licensing posture | More restrictive; limited exemptions | License required to most destinations, but broader license exceptions |
| Still a military item? | Yes | Yes — jurisdiction changed, sensitivity did not disappear |
The order of review runs one direction: USML first, then CCL. An item described on the USML is ITAR-controlled no matter how commercial it looks; an item released from the USML by a "specially designed" release provision or by ECR migration is then classified against the CCL. For a full side-by-side treatment of the two regimes — agencies, penalties, licensing, and common mistakes — see our ITAR vs EAR comparison, and for what licensing looks like once jurisdiction is settled, see ITAR export licensing.
The September 2025 USML Revisions
Effective September 2025, the State Department finalized revisions to 15 of the 21 USML categories — the most significant restructuring of the list in a decade. For classification purposes, the revisions matter in five ways:
- Modernized category descriptions in the weapons categories to align with current weapons technology;
- Updated controls on unmanned systems across multiple categories, reflecting the centrality of UAVs and UGVs in modern defense programs;
- Clarified "specially designed" criteria, reducing — but not eliminating — ambiguity in parts-level classification;
- New provisions for additive manufacturing of defense articles, addressing 3D-printed parts and the technical data files that drive them;
- Revised Category XV spacecraft controls, recalibrating the ITAR/EAR boundary for the commercial space industry.
The compliance consequence is blunt: a classification memo dated before September 2025 is presumptively stale. An item correctly classified in 2024 may now sit in a different paragraph, a different category, or a different regulatory regime entirely — and every export made under an outdated classification is potential violation exposure. We have re-baselined classification libraries for defense manufacturers since the revisions took effect, and in our experience the re-review changes the answer often enough to justify the exercise on risk grounds alone. If a re-review reveals past shipments under a wrong classification, address it promptly through a voluntary disclosure rather than hoping it goes unnoticed.
When to Seek a Commodity Jurisdiction Determination
Self-classification is the norm, and companies should perform their own documented analysis first. But when that analysis cannot confidently resolve whether an item is USML-controlled or EAR-controlled, ITAR provides a definitive mechanism: the Commodity Jurisdiction (CJ) determination under 22 CFR 120.4.
A CJ request is submitted to DDTC on form DS-4076, supported by the item's specifications, design history, performance data, and your jurisdictional analysis. DDTC coordinates with the Departments of Defense and Commerce and issues a determination — typically in around 65 business days — that is legally binding. That binding character is the point: a favorable CJ protects you from enforcement action premised on misclassification, and an unfavorable one tells you the licensing rules before a violation occurs rather than after.
Seek a CJ when:
- Your item is a commercial derivative of a military design, or a military derivative of a commercial design;
- The item sits near the USML/CCL boundary and the specially-designed analysis produces a genuinely close call;
- The September 2025 revisions changed the category text your prior classification relied on;
- A prime contractor, freight forwarder, or foreign customer disputes your classification; or
- The commercial stakes of being wrong — penalty exposure, contract eligibility, market access — are high enough that a binding answer is worth the wait.
A well-prepared CJ package is advocacy supported by engineering fact: the legal argument for the jurisdiction you believe is correct, backed by documentation DDTC can verify. This is another place the JD-plus-quality-systems combination earns its keep — we prepare the regulatory argument and marshal the technical record behind it. If you are unsure whether your situation calls for self-classification, a CJ request, or a full classification re-baseline, contact us for a free assessment.