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Short answer: freight class is a number from 50 to 500 that the National Motor Freight Traffic Association (NMFTA) system assigns to a commodity for less-than-truckload (LTL) shipping, based on density, handling, stowability and liability. Medical and laboratory supplies have no class of their own: the class follows the NMFC item number for what is actually in the carton or on the pallet, so you confirm the item number, class and measured weight and dimensions before the shipment is booked.
This page is general shipping information for people who buy, receive or ship laboratory and clinic supplies. It is not legal, customs or medical advice, and it does not assign a class to any product.
Definition and scope
NMFTA publishes the National Motor Freight Classification (NMFC). It describes the NMFC as the standard for how LTL freight is identified and classified, and says it keeps LTL shipping consistent, fair and efficient. Each product receives a class “from 50 to 500” (NMFTA, nmfta.org/nmfc, checked 2026-11-01). NMFTA’s classification page states the same range and four factors and says the correct item number helps avoid billing surprises, support safer handling and speed deliveries (nmfta.org/standards/classification, checked 2026-11-01).
Freight class applies to LTL freight, meaning shipments that share trailer space with other customers’ freight. It is separate from parcel shipping, from courier work such as medical courier services, and from the wider supply chain questions covered in medical supply logistics.
How NMFC assigns a class: the four factors
NMFTA defines the four characteristics as follows (nmfta.org/nmfc, checked 2026-11-01):
- Density: how heavy the freight is relative to the space it takes up.
- Handling: how easy it is to move across a dock and into or out of a trailer.
- Stowability: how effectively it can be stowed in a trailer for transport.
- Liability: how likely the freight is to cause damage or be damaged.
NMFTA summarises the effect this way: the denser and easier to move, the lower the class and the lower the cost; bulkier, fragile or hazardous items carry higher classes.
Applying the four factors to medical and lab supply shipments
The table below is an editorial worksheet, not a rate or class table. The left column is NMFTA’s definition; the right column turns it into a question a buyer or receiving team can ask a supplier or carrier. It deliberately assigns no class to any product, because the class belongs to the NMFC item number, not to a product category.
| NMFTA factor (source definition) | Question to ask about a supply shipment |
|---|---|
| Density: weight relative to space taken | What is the measured weight and the measured length, width and height of each handling unit as it will ship? A pallet of light, bulky consumables and a pallet of dense items are different cases. |
| Handling: ease of moving across a dock and into a trailer | Is the freight palletised or crated, or loose cartons? Does anything about the packaging make it awkward to move? |
| Stowability: how well it stows in a trailer | Can it be stacked or does it need its own space? Are there irregular shapes or items that cannot share space? |
| Liability: likelihood of damage or of causing damage | Does the load include fragile items or items classed as hazardous? Hazardous shipments carry separate rules (see below). |
How to determine freight class: a document and data checklist
NMFTA’s guidance reduces to three habits: use the correct NMFC item number, use accurate measured weight and dimensions (“never estimates”), and confirm the class before you ship. NMFTA’s ClassIT+ tool is offered to “find the correct NMFC item number, calculate density, and confirm freight class before you ship” (nmfta.org/nmfc, checked 2026-11-01).
What to have before booking an LTL shipment
- Commodity description that matches what is physically in the shipment, mixed pallets included.
- NMFC item number for each commodity, and the class that goes with it.
- Measured weight and dimensions of each handling unit, not catalogue or estimated figures.
- Piece count for the shipment.
- Accessorial needs, such as a liftgate or residential delivery, stated up front.
NMFTA’s bill of lading article says the shipper “warrants the accuracy of the commodity description, weight, piece count, and NMFC,” whether the shipper prepares the bill of lading or authorises a third party such as a 3PL or broker to do so. It adds that misstating weight, class or count can shift the outcome of a dispute or claim, that misclassified freight can trigger reweighs, reclasses and post-audit bills, and that omitting services such as a liftgate or residential delivery can delay service and raise costs (NMFTA, bill of lading article, checked 2026-11-01).
Freight class for medical equipment and NMFC item numbers
A search for “freight class medical equipment NMFC” usually expects a single number. The NMFTA material does not work that way. It ties the class to the item number and the four factors, so two shipments that are both “medical” can differ, and a shipment that mixes products may involve more than one commodity. If a supplier quotes a class, ask for the NMFC item number it comes from, and have the carrier or your logistics team confirm it against the measured weight and dimensions.
When other rules apply as well
Freight class says how a carrier prices and handles a commodity in LTL. It does not replace the rules for specific hazards or conditions. For those, see CASRAI’s guides on dry ice shipping regulations, lithium battery shipping regulations and pharmaceutical cold chain logistics. Relocating a whole facility is a different scale of freight problem; see moving a laboratory.
Common misunderstandings
- “Medical supplies have one freight class.” The class is assigned per commodity through the NMFC item number and the four factors, not by a “medical” label.
- “Density is the only factor.” NMFTA lists four: density, handling, stowability and liability.
- “An estimate is close enough.” NMFTA says to use accurate weight and dimensions, never estimates.
- “The carrier is responsible for the class.” Under the bill of lading terms described by NMFTA, the shipper warrants the accuracy of the description, weight, count and NMFC.
FAQ
What is freight class for medical supplies?
It is the NMFC class, from 50 to 500, that applies to the commodity being shipped by LTL, determined by density, handling, stowability and liability. Medical supplies are not a class by themselves.
How do I determine freight class?
Identify the commodity, find its NMFC item number, measure weight and dimensions accurately, and confirm the class before shipping. NMFTA’s ClassIT+ tool is designed for these steps.
Is there an NMFC freight class for medical equipment?
The class depends on the NMFC item number for the specific equipment as shipped (including its packaging), not on the word “medical.” Ask the supplier for the item number behind any class it quotes.
Who is responsible if the class on the bill of lading is wrong?
NMFTA states that the shipper warrants the accuracy of the commodity description, weight, piece count and NMFC, and that misclassified freight can trigger reweighs, reclasses and post-audit bills.
Sources
- NMFTA, National Motor Freight Classification: nmfta.org/nmfc, checked 2026-11-01.
- NMFTA, Classification standards: nmfta.org/standards/classification, checked 2026-11-01.
- NMFTA, Everything you need to know about a bill of lading: nmfta.org/news, checked 2026-11-01.
