GM RPO Codes Explained

RPO codes are General Motors' three-character factory option codes. They record how a Chevrolet, Buick, Cadillac or GMC was equipped at the factory, and they are what you see on an RPO build sheet: when a GM vehicle has no original window sticker on file, the VIN lookup returns its RPO codes with descriptions, when that record is available.

What is an RPO code?

RPO stands for Regular Production Option. Each code is a combination of three letters and numbers, such as Z71 or G80, that stands for one option, package, component or production instruction. A vehicle's full code list covers far more than the options a buyer chose: engine, transmission, axle ratio, paint, interior trim, emissions equipment, and processing or shipping codes that a window sticker doesn't show.

Because the list is so broad, an RPO build sheet usually runs much longer than a window sticker. It also carries no prices; original MSRP appears only on the window sticker.

• Z71
• NHT
• G80
• LS3
• L86
• AG1
• UQA
• FE9

Where are RPO codes located?

• The Service Parts Identification (SPID) label. Many GM vehicles carry this printed list of their RPO codes, most often in the glovebox; some have it on a console lid, in the trunk or near the spare tire. On older vehicles it is often faded, damaged or missing.
• The RPO build sheet by VIN. The code list recorded for that VIN, retrieved without hunting for the label. Records are not available for every vehicle.
• The original window sticker. It describes equipment in plain language for the buyer rather than listing every code, so it complements the code list instead of repeating it.

Common GM RPO code examples

Examples for illustration. A code's exact meaning can vary by model, model year and GM division, so read the description recorded for your VIN rather than relying on a general list.

Reading an RPO build sheet

Codes are not grouped by system the way a window sticker groups equipment, so it helps to know a few patterns. Many GM engine codes begin with L (L83, L86, LS3), many transmission codes begin with M, and many axle codes begin with G, including the locking rear differential G80 and axle ratios such as GU6, GT4 and GT5 (3.42, 3.73 and 4.10 on many GM trucks). These are tendencies, not rules, so always go by the description next to the code.

Two practical checks: confirm that a package claimed in a listing, such as Z71 on a truck or Z51 on a Corvette, actually appears in the code list, and remember that the list shows how the vehicle was built, not whether that equipment is still on it. To look up an unfamiliar code, browse the RPO code navigator.

What about Chrysler, Jeep, Dodge, Ram, Fiat & Alfa Romeo?

Stellantis brands don't use RPO codes. Their factory records use sales codes instead: a listing of installed equipment, each item with its code and description. For these brands the lookup returns that factory build sheet when one is available; it does not return an original window sticker or MSRP. See equipment examples by category for how factory equipment is organized, or enter a VIN to check what is on file for your vehicle.