From December 2018 the service was due to be taken over by National Express Germany; however, it withdrew from the bidding process on 25 October 2016, so the lines will continue to be operated by DB Regio Mittelfranken for the foreseeable future.

The city of Fürth sued against these plans, halting the construction and leaving sections of half built track without use.

As an "interim solution" switches are planned to be installed to connect existing quadruple track sections to the legacy alignment, but a completion date is not yet known.

[1] In late 2020 a new batch of class 1440 Alstom Coradia Continental were brought into service, replacing the last x-Wagen sets.

[3][10] Three x-Wagen sets will, however, be kept at least until the smaller timetable change in June 2021 for replacement and additional commuter services with Class 111 locomotives.

[25][26] In late September 2021 it was announced that the new Nuremberg-Würzburg high speed line which is to include a tunnel from Nuremberg to de:Bislohe, a neighborhood annexed to Fürth in 1972, was reclassified, together with other parts of the "Deutschlandtakt" concept into the highest priority group "vordringlicher Bedarf“.

[27] The new high speed line would free up capacity on existing infrastructure allowing S-Bahn service with better frequencies.

In December 2020 the ministers of transportation for Baden Württemberg and Bayern announced their intention to extend the S4 from its current endpoint at Dombühl across the state line to Crailsheim with a proposed entry into service 2024.

[51] In 2021 local farmers raised objections to the proposed closure of several level crossings as they were their principal users.

[52] Throughout the history of the S-Bahn, there have been a number of infill stations built along existing right of way to better serve certain areas.