What Are Aftermarket Parts?

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Mechanic inspecting for aftermarket or OEM parts on car
Will your insurance use generic or aftermarket parts to repair your car? Here's what you need to know. Photo: Westend61 / GettyImages

Aftermarket parts are replacement parts used in car repairs. They are not made by the car's original manufacturer, unlike original equipment manufacturer (OEM) parts, which are.

Key Takeaways

  • Aftermarket parts are replacement parts used in car repairs. They're not made by the car's original manufacturer.
  • Using aftermarket or generic parts in repairs should not interfere with your vehicle's warranty.
  • There are no safety implications of using cosmetic aftermarket parts, but structural aftermarket parts must exactly replicate the original parts to preserve the vehicle's safety and crashworthiness.
  • Policies about the use of aftermarket versus OEM parts can vary among states and insurance companies.

Definition and Example of Aftermarket Parts

Aftermarket parts are replacement parts for car repairs that are made by a company other than the car's original manufacturer. An insurance company may have the option of using aftermarket parts instead of original manufacturer parts (OEM) when it comes to repairing a car after an accident. A number of auto body shops also use aftermarket parts in repairs.

Using aftermarket or generic parts should not interfere with your vehicle's warranty. Aftermarket parts may even have longer warranties than OEM parts in some cases.


The terms of your lease will state whether using aftermarket parts in repairs is allowed if you have a leased vehicle.

Data indicates that aftermarket parts are safe. There are no safety implications of using cosmetic crash parts or aftermarket parts, but using aftermarket structural parts such as hoods may have safety implications. Aftermarket structural parts must exactly replicate the original parts to preserve the vehicle's safety and crashworthiness.

  • Alternate names: Generic parts, non-OEM parts, competitive replacement parts

How Aftermarket Parts Work

Aftermarket parts have gained popularity and acceptance as good alternatives to manufacturer parts. They may be superior to OEM parts in some cases. The manufacturers of generic or aftermarket parts may use more expensive materials or more advanced technology than a car manufacturer. 

OEM parts cost 60% more on average than the average price of a comparable aftermarket part. They're used by insurance companies and body shops when repairing vehicles after accidents because of the cost savings.

The insurance industry is regulated at the state level, so the decision to use or not to use aftermarket parts is determined state by state. States may:

  • Allow insurance companies the use of generic or aftermarket parts without the consumers' consent.
  • Require that consumers be notified if aftermarket parts were used on their vehicle.
  • Require consumer consent for the use of aftermarket parts.
  • Ban the use of aftermarket parts to repair a vehicle.


Regulations on using aftermarket parts can also vary among insurance companies. Some may require the use of OEM parts. Others may use aftermarket parts when possible to save on repair costs.

You can ask your insurance adjuster what kind of parts will be used in the repair. Some insurance companies will allow you to use OEM parts or may offer you the option with additional costs attached to cover the difference in price. 

Types of Aftermarket Parts

There are two main types of aftermarket parts. Understanding the difference can help you decide whether you're comfortable with a repair being done using generic parts, or whether you'd feel safer using OEM parts. Aftermarket parts can be either cosmetic or structural.


Cosmetic parts can impact how a vehicle functions or looks, but they don't affect its safety in a crash, such as the fenders, door skin, or trim. They don't change a car's safety and crashworthiness, so where cosmetic parts are sourced is a matter of price and availability. As long as aftermarket parts are reliable and well made, they shouldn't impact your vehicle's function, safety, or warranty.


Structural parts, such as the hood or safety cage, are responsible for absorbing the force of a crash. They protect the driver and riders. These parts should be certified by the Certified Automobile Parts Association (CAPA), which has high standards and guidelines for aftermarket parts.

The testing that the parts go through for CAPA certification must determine that they're "functionally equivalent" to OEM parts. This means they perform the same in safety tests and not simply of like kind and quality.

Aftermarket Parts vs. OEM

 OEM Parts  Aftermarket Parts
Made by the vehicle's original manufacturer Made by someone other than the original manufacturer
More expensive Less expensive
Won't impact cars' crashworthiness Won't impact cars' crashworthiness if certified
May have limited availability Easier to source and use quickly
Won't impact car warranty Shouldn't impact car warranty

The primary difference between OEM and aftermarket parts is price. Repairs are less expensive when aftermarket parts are used. This can save money for insurance companies and consumers and reduce total losses if insurance companies pay out less in claims and find less-expensive ways to repair vehicles after an accident. Consumers benefit by paying less for insurance overall when total losses paid out by insurance companies are less. They may have to adjust their overall car insurance rates when insurers pay high losses.

How to Get Aftermarket or OEM Parts

Many insurance companies may use aftermarket parts for collision repairs. There are steps you can take if you're concerned about this practice, so you can be aware and make a decision about wanting aftermarket parts used for your car.

  • Ask your insurance company: Learn what policies are in place for using aftermarket parts. Some states have laws about generic or aftermarket part use. Each insurance company may have unique conditions in its policy wordings. 
  • Know your state laws: Check with your state insurance commissioner to find out which laws apply in your state. Determine whether the insurance company is following state policies on the use of aftermarket parts.
  • Request the part you want: You can ask that OEM parts be used instead if you find out that the insurance company uses aftermarket parts. You may have to shop around for an insurance company that has an aftermarket crash parts policy that you feel more comfortable with if the insurance company denies your request.
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The Balance uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Insurance Information Institute. "FAQs About Direct Repair Programs and Generic Auto Parts."

  2. Insurance Institute of Highway Safety. "IIHS Responds to Tests Involving Aftermarket Repair Parts."

  3. American Property Casualty Insurance Association. "Aftermarket Parts Are Good For Maryland Consumers."

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