[24] AC Transit service was expanded to Fremont in November 1974, and to Newark that December, with some routes serving Union City station.

In 2008, construction started on a reconfiguration of the parking lots, which included a new station roadway connecting to Decoto Road.

[30][31][32] (Later plans have called for the Capitol Corridor to be rerouted over the Coast Line to the west, which would not permit a Union City stop).

A expanded ground-level fare lobby with provisions for future pedestrian pass-through outside the paid area was completed in 2017.

[37] Construction work on Phase 2A, which added two new escalators to the east (northbound) BART platform, took place from 2019 to December 2022.

[37] As of 2024[update], BART anticipates soliciting a developer between 2029 and 2033 for TOD to replace existing surface parking lots at the station.

[40] Some Altamont Corridor Express (ACE) services are planned to be expanded to Union City, with a new platform on the Oakland Subdivision adjacent to the BART station.