The Kia K4 sedan received the highest Top Safety Pick+ award from the American IIHS based on 2026 test results. The K4 hatchback did not receive such an award: in the updated moderate overlap frontal test, it earned a Marginal rating. 

In the other five categories, the results were almost identical. Both versions received a Good rating for small overlap and side impact, Acceptable for headlights and vehicle-to-vehicle collision prevention, and their pedestrian collision prevention system received a Good rating.

The difference manifested precisely in the moderate overlap impact at 40 mph (64 km/h). This test particularly carefully evaluates the protection of the second-row passenger. For the sedan, the rear passenger's indicators allowed it to receive an overall Good rating, while for the hatchback, the restraint system's performance and the dummy's kinematics received a Marginal rating.

At the same time, IIHS does not call the K4 hatchback an unsafe car. This refers to a specific test scenario and differences in rear passenger protection. For 2026, the requirements have become stricter: a rating below Good in this test deprives a car of any Top Safety Pick award.