During the 1960s and '70s, East Germany had modified their MiG-21PFs into a new standard, which they indigenously called the MiG-21PFM (not to be confused with the Soviet designated MiG-21PFM, a heavily upgraded MiG-21PF using the second-generation MiG-21 body style). However, a problem quickly arose when the East German air force acquired the Soviet designated PFMs, as these planes were vastly different than the upgraded PFs sharing the same name. To avoid further confusion, all Soviet designated MiG-21PFMs in German service would be re-designated into the MiG-21SPS. However, yet again, a naming convention conundrum arose when the later variant of the Soviet MiG-21PFM (Izdelyie 94A) entered service, with the biggest change being the ability to carry a GSh-23 gunpod on the underbelly. To account for the new variant again, the Germans re-designated this variant into the MiG-21SPS-K, with the K standing for Kanone to denote its ability to take a cannon pod.

Introduced as a premium pack in Update "Ground Breaking", the MiG-21SPS-K takes on an entirely new playstyle for the Fishbed family, completely departing from the high-speed, high AoA hit and run tactics of previous aircraft due to its loadouts. Due to not having a real built-in gun, this aircraft is very reliant on its IR-guided R-60 and R-13M1 and radar-guided R-3R air-to-air missile selection. However, due to being a MiG-21PFM airframe, it is limited to two hardpoints only, meaning the player can only take a maximum of four missiles. The player can also choose between either a GSh-23 gunpod, or a SPS-141 countermeasures pod on the center pylon. Overall, the SPS-K is a unique premium as it differs greatly from the usual MiG-21's gameplay loop, having to rely a lot more on its ordnance and tools than its flight performance (which as with other MiG-21s, is very good as well).

The MiG-21 SPS-K was removed from the Gaijin store at the end of the 2023 May Sale. It was made available briefly to purchase with Golden Eagles during the 2023 "MiG-21's First Flight" celebration.