This route ran several confusing service patterns between Co-op City and Pelham Bay, with only select runs continuing to Flushing.

This portion of the route across the bridge to Bruckner Boulevard was shared with the Q44, the only other local bus between the Bronx and Queens.

[2]: 11, 14 [3][9][10] North of Pelham Bay Park, the QBx1 ran several different services to different parts of Co-op City.

[6][11] The Q50, meanwhile, runs primarily between Flushing and Pelham Bay Park; there is no direct Co-op City-to-Queens service except during rush hours,[12] when Q50 buses are extended north to Erskine Place and Earhart Lane in Section 5, traveling clockwise in Co-op City northbound and counterclockwise southbound.

The Q50 employs limited-stop service, making fewer stops in Queens and bypassing the individual loops of Co-op City served by the Bx23.

[14][15] At Pelham Bay Park, both directions of Bx23 and Q50 service share three adjacent bus stops on the southbound Bruckner Boulevard to the south of the subway station.

[11][13] Prior to 2014, the Bx23 employed additional service patterns during rush hours, similar to its predecessor route.

They are among four routes (along with the Bx5 on weekends, and the Bx12 SBS) to feed into Pelham Bay Park station from the neighborhood, and the only two to serve all five sections of the development (except for the late night Bx28 service).

[2]: 4 [3][4][5] In addition, the changes were made in conjunction with controversial cuts in service to other Co-op City routes during the MTA's 2010 budget crisis,[25] and received negative input from the community.

[2]: 8 [26] 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.

[33][34] As part of the Queens redesign, the Q50 would have become the QT50, extended to LaGuardia Airport; the northern section in Co-op City would have been truncated.

[36][37] The original Queens draft plan was dropped due to negative feedback,[38] while the implementation of the Bronx redesign was postponed to mid-2022.

As a result, current Q48 service will be retained between Flushing and LaGuardia Airport, but will be rerouted from 108th Street to Seaver Way and renumbered the Q90, as the Q48 designation will be reassigned to the Glen Oaks branch of the Q46.

[50] On January 29, 2025, the current plan was approved by the MTA Board, and the Queens Bus Redesign will go into effect by Labor Day.

[55][56] This was part of the MTA's ongoing pilot program to mount bike racks on several bus routes.

[3][57] The expanded program restored bike racks on the Flushing to Co-op City bus corridor for the first time since 2005.