<p>It’s entirely possible to still get out in 4 years. The 5th year is only necessary if you fail any of the physics-related courses, as they’re only offered one quarter out of the year (ex 5B is only offered in the winter, and you can’t move onto modern physics without completion of the intro series, which means you have to wait a few more terms in order to retake and continue with the major path).</p>