Quick answer: Most standard California policies promise parts of “like kind and quality,” which lets the insurer specify aftermarket parts. But under 10 CCR §2695.8(g), any aftermarket part must be at least equal to the OEM part in kind, quality, safety, fit, and performance — and the insurer pays to make it right if it isn't.
It depends on your policy language, but California law sets a clear floor. Most standard auto policies promise repair with parts “of like kind and quality,” which lets the insurer specify non-OEM (aftermarket) crash parts. However, under California's Fair Claims Settlement Practices Regulations (10 CCR section 2695.8(g)), an insurer that specifies aftermarket parts must ensure those parts are at least equal to the OEM part in kind, quality, safety, fit, and performance. The parts must be identified on the estimate, and the insurer — not you — is responsible for the cost of returning or replacing a part that doesn't measure up, including the labor to redo the job.
OEM, aftermarket, and recycled — what the words mean
OEM (Original Equipment Manufacturer) parts are made by or for your vehicle's manufacturer — the same part the factory installed. Aftermarket parts are made by third parties. Recycled (used OEM) parts come off donor vehicles. Aftermarket parts are usually cheaper and are often fine for simple cosmetic pieces, but fit and metallurgy vary, and on late-model vehicles with sensors, crumple zones, and ADAS hardware behind the bumper covers, part quality is a safety question, not just a cosmetic one.
When OEM parts are the right call
Some situations tilt strongly toward OEM: leased vehicles (many lease agreements require OEM), vehicles still under factory warranty, structural components, and any panel or bracket that a driver-assistance sensor mounts to or reads through. Some insurers offer an OEM parts endorsement you can add to your policy for a few dollars a month — worth asking about before you ever need it.
What to do if the estimate lists aftermarket parts
If your insurer's estimate lists aftermarket parts and you want OEM, you have options: ask whether the policy or state law requires OEM in your situation, ask the shop to document why OEM is justified (fit, safety, sensor mounting), or pay the difference out of pocket. In practice, adjusters approve OEM more often when the shop documents the reason well. This is closely related to why shop and insurer estimates differ — documentation moves numbers.
At Spark Collision Center in Fremont, we flag every part type on your estimate in plain English — OEM, aftermarket, or recycled — and we tell you when we think an aftermarket part is genuinely equivalent and when it isn't. We've put thousands of panels on Fremont commuter cars and fleet vans, and we don't install parts we wouldn't put on our own trucks.