Bellevue commuters paying into Sound Transit's tax district won't see the 4 Line connecting South Kirkland to Issaquah until 2050 at the earliest.

The time estimate comes as the agency's board committed $406.8 million June 25 to push West Seattle's light rail extension into final design.

The vote, adopted by at least a two-thirds supermajority under Resolution R2026-14, is the first major spending action since the board's May 28 ST3 rebalancing, which addressed a $34.5 billion funding gap by delaying projects across the region. Board Chair Dave Somers signed the resolution.

The bulk of the money goes to two contracts: $341 million to Jacobs Engineering for final design work on the West Seattle Link Extension, and $48.7 million to Connect Seattle Partners (a joint venture of Mott MacDonald and WSP) for program management on both the West Seattle and Ballard Link projects.

"These are among the first steps we're taking following the adoption of our updated plan," Somers said. "We're moving forward with urgency."

West Seattle Link, currently at 30% design, would add 3.9 miles of rail and three new stations between SoDo and Alaska Junction. Sound Transit's target opening is 2032. The project is the only Sound Transit extension with a federal Record of Decision, issued April 29, 2025. However, agency leadership has acknowledged the project is unlikely to break ground without a full funding grant agreement from the Federal Transit Administration, and the Trump administration has not approved any new transit grants since January 2025.

The South Kirkland–Issaquah Link (4 Line), which would connect to the existing 2 Line already serving Bellevue's Spring District and East Main stations, remains funded through construction under the May 28 rebalancing.

But its opening was pushed from 2041 to 2050, and the board transferred $100 million from the 4 Line to fund a Renton Transit Center parking garage in a 15-3 vote that same night.

King County Councilmember Claudia Balducci, who represents much of the Eastside on the Sound Transit Board, voted against the May 28 rebalancing plan.

"We are a transit agency, not a parking agency," Balducci said of the $100 million transfer. "We should not take money out of our primary mission to do an important, necessary, but ancillary service."

Options still under study for the 4 Line include connecting into the 2 Line closer to South Bellevue Station and building primarily in state right-of-way.

The board directed staff to develop an adaptive program management plan by the end of 2026. For West Seattle Link, the next board action will likely be a construction authorization vote, though no date has been scheduled.

Sound Transit collects roughly $700 per resident per year in taxes across its district, according to Construction Dive's analysis of agency financials.

Residents can submit public comment at Sound Transit Board meetings or through the agency's online portal at soundtransit.org.