Shinjuku Line
From December 2001, the 215 series fleet was removed from Tōkaidō Line "Acty" services, and reassigned to new Shōnan-Shinjuku Line services between Shinjuku and Yokosuka. Their use on Shōnan-Shinjuku Line services continued until 16 October 2004, from which date all Shōnan-Shinjuku Line services were standardized with E231 series rolling stock.