Chevrolet Bolt EV front and rear turn signal bulbs use a 7440NA size bulb across all positions. The replacement chart covers 2017 to 2020 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Chevrolet Bolt EV uses the 7440NA bulb in both the front and rear turn signal positions across the 2017-2020 model years.
The 7440NA is a single-filament wedge bulb in the T20 form factor, rated at 12 volts and 21 watts.
The "NA" suffix in the 7440NA designation indicates natural amber glass, meaning the amber color is produced by the glass envelope itself rather than by an amber-coated or clear bulb paired with a colored lens.
The 7440NA conforms to ANSI standards applicable in both the United States and Canada, placing it within a regulated performance and fitment classification.
Because the same bulb number applies to all four turn signal positions on the Bolt EV for the full 2017-2020 span, a single bulb type covers both axles of the vehicle.
The 7440 base type belongs to the W21W wedge family, and the single-filament construction means it is dedicated solely to turn signal or similar single-function applications, with no secondary filament for combined stop or running light duties.
Substituting a clear 7440 in place of the 7440NA would alter the color output at the lens, as the natural amber glass is integral to the bulb meeting amber turn signal color requirements rather than relying on an external filter.