After a collision your repair estimate may reference parts described in terms your insurance company is hoping you will not question. OEM and aftermarket are the two categories that affect your repair quality, your vehicle's resale value and in some cases your factory warranty.

Here is what the terms actually mean and what your insurer may not volunteer.

What OEM Means

OEM stands for Original Equipment Manufacturer. OEM parts are produced by or for the vehicle's manufacturer to the same specifications as the parts on your car when it left the factory. They fit correctly, match your paint code and meet your manufacturer's safety and structural standards.

What Aftermarket Means

Aftermarket parts are produced by third-party manufacturers who were not involved in building your vehicle. Quality varies significantly. Some aftermarket parts are well-made and fit correctly. Others have fitment gaps, different metal thickness or finishes that do not match your original paint. The price difference is real — aftermarket parts cost less — which is why insurers often push for them.

What Your Insurance Policy Actually Says

Most standard auto insurance policies allow insurers to specify aftermarket parts for repairs as long as those parts are "like kind and quality" to the original. The problem is that "like kind and quality" is a standard that is difficult to enforce after the fact. If a door panel that looked fine on the estimate has a 3mm gap at the body line when installed, disputing it becomes your problem, not the insurer's.

In Colorado you have the right to request OEM parts. Depending on your policy and the age of your vehicle, your insurer may be required to cover them or may cover the cost difference. Ask before you approve the estimate.

When OEM Parts Are Non-Negotiable

For certain vehicles and certain repairs, aftermarket parts are not a reasonable substitute.

Certified repairs on vehicles under manufacturer warranty

BMW, for example, requires OEM parts and procedures as a condition of certification. Using aftermarket parts on a certified BMW repair voids the factory warranty.

Structural components

Aftermarket metal for frame, unibody or structural rails may not meet the same yield strength specifications as OEM. In a subsequent collision these components behave differently than the manufacturer designed.

Advanced driver assistance system (ADAS) components

Sensors, cameras and radar units must be factory-spec. Aftermarket substitutes may not calibrate correctly to manufacturer specifications.

Leased vehicles

Lease agreements typically require OEM parts for repairs. A dealer inspection at lease return that identifies aftermarket components can result in charges.

How to Handle This With Your Insurer

When you receive your repair estimate ask the shop to identify every part listed as aftermarket or non-OEM. Then contact your insurer and request OEM substitution citing your policy's like kind and quality standard. A shop that handles insurance claims directly will do this on your behalf. You should not have to negotiate parts specifications yourself.

SVE Autobody works directly with your adjuster from estimate to completion. We identify every part specification before work begins and push back on aftermarket substitutions where OEM is required for structural integrity, warranty preservation or ADAS calibration. If your vehicle is BMW certified, every part is OEM. No exceptions.