[7] Pierce Transit began expanding outside of Tacoma on July 1, 1980, with new routes to Federal Way, Fife, Milton, Puyallup, Sumner, Fort Lewis, and McChord Air Force Base.

[9] These new routes competed with an existing private operator, who filed a lawsuit to halt Pierce Transit's expansion after negotiations broke down.

[11] Pierce Transit began operating direct express bus service from Lakewood and Tacoma to Downtown Seattle on September 17, 1990.

[13] On June 14, 1993, the agency opened a major transit center on Commerce Street in Downtown Tacoma that would serve 1,300 buses on a typical weekday.

[20][21] In 2012, Pierce Transit argued that it was in an unsustainable state due to its reserves running out, and as a result, must cut service by 53% in order to become sustainable again.

[25] In May 2012, the cities of Bonney Lake, Buckley, DuPont, Orting, and Sumner withdrew from Pierce Transit's PTBA after their local bus routes had been cut.

[27] During the early stages of the COVID-19 pandemic in 2020, Pierce Transit laid off or furloughed 90 employees amid a projected revenue cut of $47 million due to low ridership and sales tax returns.

[31] It was originally scheduled to begin construction in 2021 and open by 2024 at a cost of $95 million, with funds from Sound Transit 3 and the federal government.

[29] In August 2023, the board of commissioners voted to defer work on the bus rapid transit project due to its six-year delay and $150 million cost increase.

[32] The service retains the "Stream Community Line" moniker and a 28-year naming rights sponsorship with health system MultiCare valued at $9.3 million.

[33][34] The agency has also studied several four additional routes for future expansion of the Stream bus rapid transit system to serve Lakewood, South Tacoma, and Puyallup.

[27] Areas served include Auburn, Edgewood, Federal Way, Fife, Fircrest, Gig Harbor, Joint Base Lewis–McChord, Lakewood, Milton, Pacific, Purdy, Puyallup, Ruston, South Hill, Steilacoom, Tacoma and University Place.

[39] Fares last updated on: 3/1/2016 [40] In 1986, Pierce Transit began experimenting with compressed natural gas as a fuel source for its bus fleet by modifying two existing buses, becoming the first agency in the nation to do so.