T-Mobile Park is a retractable roof ballpark in Seattle, Washington, United States. It is the home stadium of the Seattle Mariners of Major League Baseball and has a seating capacity of 47,368. It is in Seattle's SoDo neighborhood, near the western terminus of Interstate 90 and is owned and operated by the Washington State Major League Baseball Stadium Public Facilities District. The first game at the stadium was played on July 15, 1999.

During the 1990s, the suitability of the Mariners' original stadium, the Kingdome, as an MLB facility came under question, and the team's ownership group threatened to relocate the team. In September 1995, King County voters defeated a ballot measure to secure public funding for a new baseball stadium. Shortly thereafter, the Mariners' first appearance in the MLB postseason and their victory in the 1995 American League Division Series (ALDS) revived public desire to keep the team in Seattle. As a result, the Washington State Legislature approved an alternate means of funding for the stadium with public money. The site, just south of the Kingdome, was selected in September 1996 and construction began in March 1997. The bonds issued to finance the stadium were retired on October 1, 2011, five years earlier than anticipated.

T-Mobile Park is also used for amateur baseball events, including the Washington Interscholastic Activities Association high school state championships and one Washington Huskies baseball game per season. Major non-baseball events that have been held at T-Mobile Park include the 2001 Seattle Bowl, WrestleMania XIX in 2003, which attracted the stadium's record attendance of 54,097, and the 2024 NHL Winter Classic.

The stadium was originally named Safeco Field under a 20-year naming-rights deal with Seattle-based Safeco Insurance. T-Mobile acquired the naming rights on December 19, 2018, and the name change took effect on January 1, 2019.

Location and transportation T-Mobile Park is in the SoDo district of downtown Seattle, bounded by Dave Niehaus Way (a block of 1st Avenue S.) to the west, Edgar Martínez Drive (formerly S. Atlantic Street) to the south, Royal Brougham Way to the north, and BNSF railroad tracks to the east.

Parking is available at the stadium's parking garage across Edgar Martínez Drive, the Lumen Field garage to the North, and other privately operated lots in the area. Sounder commuter rail serves nearby King Street Station. T-Mobile Park is also served by the 1 Line of Sound Transit's Link light rail system and local King County Metro and Sound Transit Express bus routes at the nearby Stadium station.

Events at T-Mobile Park are scheduled to avoid conflicts with Lumen Field, which is directly north of the stadium. The Mariners have priority for schedule slots per an agreement reached with the Seattle Seahawks, who play at Lumen Field.

A dedicated ride-hailing lot opened in June 2023 along 3rd Avenue; it cost $2.8 million to construct and opened ahead of the 2023 MLB All-Star Game.

History On March 30, 1994, county executive Gary Locke appointed a task force to assess the need for a new baseball stadium to replace the rapidly deteriorating Kingdome. Many feared that the Mariners would leave Seattle if a new stadium was not built. In January 1995, the 28-member task force recommended to the King County Council that the public should be involved in financing the stadium. The task force concluded that a sales tax increase of 0.1% (to 8.3%) would be sufficient to fund the stadium. King County held a special election on September 19, asking the public for this sales tax increase; the measure led early, but was narrowly defeated by one-fifth of one percent.

On October 14, a special session of the state legislature authorized a different funding package for a new stadium that included a food and beverage tax in King County restaurants and bars, car rental surcharge in King County, a ballpark admissions tax, a credit against the state sales tax, and sale of a special stadium license plate. Nine days later, the King County Council approved the funding package, and established the Washington State Major League Baseball Stadium Public Facilities District to own the ballpark and oversee design and construction. Taxpayer suits opposing the legislative actions and the taxes failed in the courts.

Initial concepts for the new stadium, developed under the working name of New Century Park, were unveiled by architecture firm HOK in March 1995. The design included a retractable roof split into four sections and a seating capacity of 45,000 seats on four levels. On September 9, 1996, the site was selected for the new stadium, just south of the Kingdome. In late fall, several members of the King County Council wrote a letter to the Seattle Mariners, requesting a postponement of the projected $384.5-million stadium project.

Construction officially began in 1997, with a groundbreaking ceremony on March 8 featuring Mariners star Ken Griffey Jr. The construction, overseen by chief financial officer (and former team president and minority owner) Kevin Mather, continued through the beginning of the 1999 season. Its first game was on July 15, immediately after the All-Star break; the Mariners lost 3–2 to the San Diego Padres with 44,607 in attendance. Longtime team broadcaster Dave Niehaus threw out the ceremonial first pitch at the game to Tom Foley, the former Speaker of the United States House of Representatives.

The naming rights were sold in June 1998 to Seattle-based Safeco Insurance, which paid $40 million for a 20-year deal. The 2018 season was the last played under this name, and the Safeco signage was removed from the ballpark beginning that November. The naming rights were awarded to T-Mobile, whose U.S. headquarters are based in nearby Bellevue on December 19, which paid $87.5 million for an agreement that will last 25 years, and the name change officially took effect on January 1, 2019.

Ken Griffey Jr. returned to Safeco Field in 2007 with the Cincinnati Reds (where he had been traded after the 1999 season) to a hero's welcome. In commemoration of Griffey's achievements with the team, the Mariners unveiled a new poster that declared Safeco Field "The House That Griffey Built."

The Mariners moved the fences at Safeco Field closer to home plate before the 2013 season "to create an environment that is fair for both hitters and pitchers," according to general manager Jack Zduriencik. Safeco Field had been considered one of the most pitcher-friendly ballparks in the majors since it opened. The center field scoreboard and ad panels were replaced with an board during renovations, becoming the largest among all stadium scoreboards in the major leagues at the time.

After the 2017 season, the field surface, in place since the stadium opened in 1999, underwent its first full replacement. The infield and foul territory were redone in 2012, but the outfield had not been replaced before the resodding.

On January 1, 2024, the National Hockey League (NHL) hosted the 2024 NHL Winter Classic, where the Seattle Kraken won over the Vegas Golden Knights 3–0.

Features

T-Mobile Park covers an area of and incorporates of gross interior space. The playing field uses a mix of Kentucky bluegrass and overseeded perennial ryegrass that is supplied by a sod farm in Moses Lake, Washington. During colder months, the grass is kept warm through a series of underground heaters that stimulate growth. Artificial lights are used for areas with less sunlight, such as the right field and first base sideline. During special events on the field, such as concerts, the grass is covered by portable flooring tiles; damaged sections are then replaced using new deliveries from the sod farm or patches grown behind the center field wall.

There previously was technology that allowed spectators to monitor special game-time features with Nintendo DS receivers.

Layout There are five main levels to the stadium: Field (or Street), Main Concourse (100 level), Club Level (200 level), Suite Level, and the View Level (300 level). The Main Level has 20,521 seats—the most of any section—and encompasses most of the lower bowl. There are 4,123 seats in the Club Level, 2,050 seats in the Suite Level, and 15,902 seats in the View Level. Two bleacher sections are above left field and below the center field scoreboard, with 3,666 seats. The field sits approximately at street level, requiring visitors to ascend stairs, escalators, or elevators to access the main concourse from the entrances, with the exception of the Right Field Entry, which opens onto the main concourse.

T-Mobile Park has several themed terrace areas, including the T-Mobile 'Pen behind left and center field; and the Trident Deck on the View Level. A short boardwalk runs along 1st Avenue on the View Level with views of Puget Sound and the city skyline. The press box, named the Dave Niehaus Broadcast Center, is on the Club Level and sub-level behind home plate. It was named for longtime Mariners broadcaster Dave Niehaus; after his death, his headset and microphone were placed by his empty seat in the Broadcast Center as a tribute. The stadium has an attached parking garage with 1,800 stalls that is supplemented by unofficial lots in the area as well as the adjacent Lumen Field garage.

Seating capacity YearsCapacity1999–2002 46,6212003 47,7722004–2008 47,4472009–2011 47,8782012 47,8602013–2014 47,4762015 47,5742016–2017 47,9432018 47,7152019 47,9292020 47,5002021 47,4802022 47,3782023 47,3492024 47,3762025–2026 47,368

Food service

T-Mobile Park offers greater food and beverage selection than typical ballparks. It includes concession stands operated by chain as well as local restaurants, such as Ivar's, Kidd Valley, and Salt & Straw. Patrons could previously order food with a Nintendo DS app called Nintendo Fan Network. The ballpark debuted "Walk-Off Market", the first cashierless store in an MLB stadium, in May 2022 using technology supplied by Amazon. Three additional locations the following season and include grab-and-go food and beverages.

Retractable roof

In the open position, the roof rests over the BNSF Railway tracks that bound the stadium to the east, with part of it hanging over the stands in right field. This has the effect of echoing the whistles from passing trains into the stadium. Train horns were often heard inside the stadium throughout the 2000s, but abated significantly when an overpass was built for Royal Brougham Way, the street that bounds the stadium to the north which previously crossed the tracks. Unlike other stadiums with retractable roofs, the roof at T-Mobile Park does not fully enclose the ballpark; this allows the wind and temperatures to still impact the game with the roof closed.

The roof covers approximately and weighs . It moves with 128 wheels that move along rails on the north and south side of the ballpark. The top of the roof is above field level, while the bottom is high. The roof takes 10 to 20 minutes to open and is moved 300 to 500 times per year, mostly to manage the stadium's grass. The Mariners play an average of 17 to 18 games per season with the roof closed, the least among MLB ballparks with retractable roofs. From 1999 to 2024, the roof had been used for 435 games—22 percent of those played at the stadium—with a maximum of 25 games during the 2010 season. The Mariners had a 843–737 record in games with the roof open, 145–133 with it closed, and 81–76 in games where the roof moves.

Scoreboards