OEM parts
OEM parts are collision replacement parts made by the vehicle manufacturer or its licensed supplier, sold through the manufacturer parts channel to the shop that is doing the repair.
Collision Bureau is not a law firm and this is not legal or medical advice. It is general information about what happens after a crash. For advice on your situation, talk to an attorney licensed in your state or a treating clinician.
What it means
OEM is shorthand for Original Equipment Manufacturer. An OEM part is the same part the factory used to build the car in the first place, or a part the manufacturer licenses a supplier to produce under its name, routed to the shop through the manufacturer parts channel. The part number on the box matches a part number in the manufacturer catalog. The dealer parts counter is a common source. The point of the term is to distinguish parts that came through that channel from parts that look similar but came from somewhere else.
How it works
In a collision estimate, every replaceable part has a line, a part number, and a source. The source is the field that answers the OEM question. An OEM line names the manufacturer, an aftermarket line names a third-party producer, and a recycled or LKQ line names a salvage source. The write-up calculates the total using whichever source the shop and the insurer agreed to on that line, which is why reading an estimate means reading the sources beside the operations. Changing the source changes the dollars and sometimes changes the operations around the part, because fitment affects labor.
Why it comes up
The parts conversation shows up every time an insurer and a shop are writing an estimate together. Many policies let the insurer specify parts of like kind and quality, which in practice includes aftermarket and recycled sources at the insurer's discretion. Some policies include OEM endorsements that require OEM parts for a defined period after purchase. Some states have statutes about disclosing non-OEM use and getting the owner's written consent. The owner's role is to read the final write-up and look at the sources before the keys change hands. If you want help translating a write-up, you can ask for help with the repair.
What it is not
OEM is not a warranty against defect, which the manufacturer and the shop handle under their own terms. It is not a guarantee that every panel on the car is OEM after a repair, because a mixed source estimate is common. It is not the same as a dealer repair, because a dealer and a body shop are different operations even when they share a parking lot. And it is not interchangeable with the term certified, which refers to a shop that has met a manufacturer's training and tooling standards, a separate concept from the source of a part.
Questions people actually ask
01Will the insurer always pay for OEM parts?
Not automatically. Many policies include a parts clause that allows the insurer to specify like kind and quality parts, which in practice covers aftermarket and recycled sources alongside OEM. Some policies include endorsements that require OEM for a defined window after purchase, and some states regulate when non-OEM can be used without written consent. What your policy and your state actually require is a question for your declarations page, your insurer, and a licensed attorney in your state.
02Does the shop have to use OEM if the owner asks?
The shop can order whatever the owner is willing to pay for, and the insurer will pay only up to what the policy covers. If the policy allows a non-OEM part at a lower price and the owner wants OEM, the owner can usually pay the difference out of pocket and the shop will install the OEM piece. The write-up has to show the two numbers clearly. The decision is a budget question for the owner and a documentation question for the shop.
03Are OEM parts always better?
They are built for the vehicle in question and come through the manufacturer parts channel, which is why they match on fit and finish without surprises. For body panels, bumpers, lamps, and anything attached to a safety system, matching matters because the piece has to work with sensors, mounts, and crumple paths designed around that exact part. For other items the gap between an OEM piece and a quality aftermarket piece is narrower. The answer for a specific car is a conversation between the owner and the shop.