The BVG Class IK is a type of electrical multiple unit used on the Berlin U-Bahn.

In August 2011, BVG announced an order of IK series to replace A3L71 stock which had reached the end of its working life.

Two prototypes were bought from Stadler Rail with the remaining 38 units being delivered between 2015 and 2017.

With the delivery of the first IK20 unit 5065 on 25 May 2020 during the COVID-19 pandemic, the next delivery series of the IK series began, which again, like the IK17, would initially be in the large profile on the U5 line in order to have enough rolling stock for the planned end of 2020, to have a connection to Berlin Hauptbahnhof.

Significant differences to previous series are, for example, the new seat upholstery with the name "Urban Jungle", which is based on the well-known worm pattern from older BVG series and can already be found in new vehicles in the bus sector.