The award applies to models with the optional front-crash prevention system called EyeSight.
"In IIHS track tests of an Impreza equipped with the technology, the system avoided collisions at both 12 and 25 mph, earning a superior rating," the Institute said in a statement on Friday. "The system also includes a warning feature to try to prompt the driver to respond before the automatic braking is initiated."
The 2015 Impreza is on sale now at Subaru dealerships.
The National Highway Traffic Safety Administration also gave the 2015 Impreza sedan and hatchback the top five-star safety rating.
The 2015 Impreza earned four stars in the front crash test and five stars in the side and rollover crash tests, NHTSA said.
Edmunds says: Some important safety information for car shoppers considering the 2015 Subaru Impreza.