Service was partially extended to East Bay Avenue-Hunts Point Avenue in November 1967, and then to its current terminus in July 1974.

On February 19, 1984, the entire Bronx bus system was revamped, with several routes renumbered, merged or eliminated.

[8] The former Bx34A rush hour-only shuttle service, running only within the eastern and western areas of Hunts Point, became part of the Bx6 in February 1984.

The western branch of Hunts Point was eliminated in 1990, and was not replaced by another service until the Barreto Pool Shuttle (current Bx46) started serving the area in July 2008.

The Bx6 SBS supplements the existing Bx6 local service, making stops at select high-ridership locations and all transfers points to Metro-North and subways.

As part of the MTA's 2017 Fast Forward Plan to speed up mass transit service, a draft plan for a reorganization of Bronx bus routes was proposed in draft format in June 2019, with a final version published in October 2019.

In February 2022, it was announced that the modifications would take place on June 26, 2022, however the Bx6-SBS rerouting to Soundview would be delayed until 2024, after OMNY fully replaces MetroCard.