GMC Sierra Luggage Compartment Bulb Size

GMC Sierra luggage compartment bulb sizes include 921 and 912 specifications for this vehicle model. The replacement chart covers 1999 to 2020 production years with corresponding bulb size data.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2015-2020	921
2014	921 (1500 only)
2014	912 (3500 HD only)
1999-2013	912

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912

Other Locations

Additional Notes

The GMC Sierra uses two bulb sizes for its luggage compartment across its model years: the 921 and the 912, both of which are ANSI-standardized wedge-type bulbs rated at 12 volts and sharing the T15 form factor.
The 912 bulb draws 12 watts, while the 921 draws 16 watts. Although the 912 is a variant of the 921 and the two share the same T15 wedge base, their wattage difference makes them non-interchangeable without consideration of the vehicle's electrical expectations.
The GMC Sierra (1500) uses the 921 bulb for the 2014 model year, while the Sierra 3500 HD of the same year uses the 912, making 2014 the only model year in the specifications where bulb fitment differs by trim or configuration.
The 921 bulb applies to the GMC Sierra for model years 2015-2020, as well as the 1500 variant of the 2014 model year.
The 912 bulb applies to Sierra model years 1999-2013, as well as the 3500 HD variant of the 2014 model year.
Both the 912 and 921 are classified under ANSI standards applicable in the United States and Canada, indicating a standardized design intended for consistent manufacturing tolerances across compliant bulb producers.