OEM, Aftermarket, and Used Parts: What Is the Difference?

When you look at a collision repair estimate, you will see part numbers and prices — but not always a clear explanation of what kind of parts are being used. That distinction matters more than most consumers realize.

Here is a plain-English breakdown of the three types of replacement parts, and what each one means for your repair.

OEM Parts

OEM stands for Original Equipment Manufacturer. These are parts made by or for your vehicle's manufacturer — the same source as the parts that were on your car when it left the factory.

OEM parts are designed to fit exactly. They go through the same manufacturing tolerances as the originals. For structural components, safety systems (like crumple zones and bumper reinforcements), and sensors, this precision matters.

When to care most about OEM:

  • Late-model vehicles still under the manufacturer's bumper-to-bumper warranty (non-OEM parts may void that warranty)
  • Safety-related components: airbag sensors, bumper reinforcements, structural panels
  • Vehicles with advanced driver assistance systems (ADAS) — sensors and cameras need precise fitment to calibrate correctly
Typical cost: The most expensive option. Insurance companies often prefer alternatives to reduce claim costs.

Aftermarket Parts

Aftermarket parts are made by third-party manufacturers — companies other than your car's brand. The quality range here is wide.

Some aftermarket suppliers make parts that are virtually indistinguishable from OEM in fit and quality. Others make parts that do not fit well, wear faster, or are not certified to meet safety standards. The insurer typically does not specify which aftermarket supplier will be used — just "aftermarket."

The CAPA certification question: The Certified Automotive Parts Association (CAPA) certifies some aftermarket parts for fit, finish, and performance. If your estimate lists aftermarket parts, you can ask whether they will be CAPA-certified. Not all shops honor this request, but it is worth asking.

When aftermarket is less of a concern:

  • Cosmetic parts on older vehicles (fenders, hoods, bumper covers) where exact factory spec is less critical
  • High-mileage vehicles where the cost difference is significant relative to the car's value
When to push back on aftermarket:
  • Structural components (frames, structural pillars, bumper reinforcements)
  • Airbag sensor mounting points
  • Newer vehicles where fit problems will be obvious

LKQ / Used Parts

LKQ stands for "Like Kind and Quality" — it is industry shorthand for used parts pulled from salvage vehicles. You may also see these listed as "recycled" or "salvage" parts on an estimate.

Used parts come from cars that were in accidents, flooded, or otherwise totaled. The part itself may be in good condition, or it may have hidden wear or damage.

Legitimate uses for LKQ parts:

  • Sheet metal on high-mileage older vehicles where originality is not a concern
  • Mechanical components that are easy to inspect and test
  • Parts that are no longer available new (older vehicles)
Where LKQ parts raise concerns:
  • Any structural component
  • Safety systems
  • Parts with surface corrosion or damage that is hard to see during the initial inspection
  • Items that will be painted — used parts may have imperfections that show through the finish
If your estimate lists used parts, ask the shop to show you the specific part before it is installed, and confirm its condition.

Remanufactured / Reconditioned Parts

A fourth category worth knowing: remanufactured or reconditioned parts. These are used parts that have been professionally rebuilt — cleaned, re-machined, or refinished to bring them back to a functional standard.

Common examples: alternators, starters, wheel assemblies, and some bumper covers. These are typically a middle ground in cost between new aftermarket and straight LKQ.

Quality varies by supplier. Ask the shop which supplier they use for reconditioned parts if this comes up on your estimate.

Your Rights Regarding Parts

You have the right to ask what parts will be used on your vehicle. A reputable shop will tell you clearly.

You may have the right to OEM parts under your policy. Some insurance policies guarantee OEM parts for vehicles under a certain age (often 2-3 years) or under the manufacturer's warranty. Read your declarations page or call your insurer and ask directly.

Some states require consumer consent for non-OEM parts. A handful of states — including California — have laws requiring insurers to disclose when non-OEM parts are being used and, in some cases, requiring your consent. Laws change, so check your state's current regulations or ask your insurance agent.

You can pay the difference. Even if your insurer only covers aftermarket or used parts, you can typically pay the difference out of pocket to get OEM parts installed. Ask your shop to price out both options.

Key Takeaways

  • OEM = factory-spec parts from your manufacturer. The most precise fit, usually the most expensive.
  • Aftermarket = third-party-made parts. Quality varies widely. Ask if they are CAPA-certified.
  • LKQ/Used = parts pulled from salvage vehicles. Lower cost, but condition and fit require scrutiny.
  • You have the right to know what parts will be used on your car before work begins.
  • For safety-related components and newer vehicles, OEM parts are worth the extra cost in most cases.

Curious about how your estimate is structured? Read our guide on [how to read a collision repair estimate](/learn/how-to-read-an-estimate).