Toyota Prius front turn signal bulbs use 7440NA, 7443NA, or 7444NA sizes, while rear turn signal bulbs use 7440NA or 7440 sizes according to the replacement bulb chart. The specifications cover a 22-year range from 2001 through 2022.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 7440NA is the most widely used bulb type across the Toyota Prius turn signal specifications, appearing in both front and rear positions across the majority of model years covered. It is a single-filament T20 wedge bulb rated at 12V and 21W, distinguished from the base 7440 by its natural amber glass envelope, which produces an amber signal output without relying on a colored lens or reflector housing.
The base 7440 and the 7440NA share the same electrical ratings of 12V and 21W and the same single-filament T20 wedge form factor. The sole difference is that the 7440 uses clear glass while the 7440NA uses natural amber glass. The rear turn signal specifications for the 2001-2003 Toyota Prius list the clear-glass 7440, while all subsequent rear turn signal years list the 7440NA.
The 7443NA and 7444NA are dual-filament T20 wedge bulbs, each rated at 12V with a 21W main filament and a 5W secondary filament. The secondary filament allows a single bulb to serve two lighting functions simultaneously, such as turn signaling and parking light operation, within the same housing.
The front turn signal position on the Toyota Prius for 2016 and 2018 requires either a 7440NA or a 7443NA depending on whether the vehicle is equipped with LED parking lights. Trims with LED parking lights use the single-filament 7440NA, while trims without LED parking lights use the dual-filament 7443NA, which handles the additional parking light function through its secondary filament.
The 2017 front turn signal specification follows the same LED-dependent split but uses the 7444NA instead of the 7443NA for trims without LED parking lights. Although the 7443NA and 7444NA share identical electrical ratings and the same T20 wedge base, they carry distinct ANSI designations and are not confirmed as interchangeable within these specifications.
Installing a single-filament 7440NA in a front turn signal socket that requires a dual-filament 7443NA or 7444NA would leave the parking light function of that housing without a working filament. The physical T20 wedge base is shared across all four bulb types, so the socket will accept any of them mechanically, making the filament count a critical distinction that the socket itself does not enforce.
All four bulb types listed in the specifications conform to ANSI standards applicable to the United States and Canada, indicating a standardized base and electrical interface across the range. The T20 wedge base is a common automotive format, and the 12V operating voltage is consistent with standard 12-volt vehicle electrical systems.
The front turn signal specifications for the Toyota Prius span 2001-2018, while the rear turn signal specifications include 2001-2019 and 2022, with no conditional fitment notes appearing in the rear position across any of those years.