GM RPO codes: how to read the SPID label

RPO stands for Regular Production Option. GM’s body builder manuals describe the RPO list as the codes “that are available on the vehicle” and say the vehicle’s own RPO list is printed on the Service Parts Identification (SPID) label. Each code is three letters or digits: L87 is a 6.2L V8, GU6 a 3.42 rear axle ratio, Z71 the off-road chassis package.

The codes describe how the vehicle was built at the factory, which is why parts counters, body builders and buyers use them. They do not tell you anything about what happened to the vehicle since. Codes vary by model year and market, so treat the table below as a guide and check your own vehicle’s list.

The SPID label is a paper sticker, usually in the glove box, the trunk or the spare tire area. GM’s owner’s manuals say it lists the VIN, the model designation, paint information and production options and special equipment, and ask owners not to remove it.

Paper label. After the VIN and model, the label prints rows of three-character codes. Each one is an RPO. Look them up in the table below, or in the RPO list in your vehicle’s service or body builder manual.

QR code (2018 and later). Any phone QR reader works. GM’s example scan returns the VIN, model year, model code, a date and then the RPO codes, separated by spaces. GM notes the scan does not include descriptions; they are in the service manual under General Information.

Window sticker. When GM’s window-sticker service has the VIN on file, the original sticker PDF carries the RPO codes in its text layer. They aren’t printed on the sticker, but you can search the PDF for a code or copy the codes out. GM doesn’t publish which model years include them. In our checks, 2022 to 2025 vehicles worked and a 2017 didn’t. Our Chevrolet build sheet page builds that link for your VIN.

Every code below appears in the RPO code list of at least one GM body builder manual (2025 Silverado and Sierra 1500, Silverado and Sierra HD, Express and Savana, and the 2023 Escalade). The source wording column is GM’s own description. Codes vary by model year and market, and a code that is listed here may not be offered on your vehicle.

An RPO list tells you how a vehicle left the factory. It does not show accidents, title brands or open recalls. Before you buy, decode the VIN, run the free recall check, and consider a history report.

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Each page covers the official window-sticker lookup, where the VIN is and the official recall lookup for that brand:

• Chevrolet build sheet and window sticker by VIN
• GMC build sheet and window sticker by VIN
• Cadillac build sheet and window sticker by VIN
• Buick build sheet and window sticker by VIN

Other brands use other systems: see Mercedes-Benz option codes and BMW option codes.