U-turn allows the user to switch out to its Poké Ball immediately after inflicting damage to the foe. If there is only one Pokémon left in the user's team or if the user is a wild Pokémon, no secondary effect will apply. It shares this effect with Volt Switch.
As of 1.2.1, there is a bug that makes U-turn passes stat changes from the user to the ally that switches in, similar to Baton Pass.