Parsons Corporation is an American multinational technology-focused defense, intelligence, and infrastructure engineering firm. Founded in 1944, Parsons is headquartered in Chantilly, Virginia, and serves both government and private sector organizations in more than 30 countries.
Parsons became a public company after its initial public offering (IPO) in 2019. It was included in the Fortune 1000 in 2020 and added to the S&P 400 in 2024. As of late 2025, Parsons employs over 21,000 professionals worldwide.
History
Parsons was founded by Ralph M. Parsons in 1944. Emerging at the end of World War II, Parsons' location in Los Angeles, proximity to organizations such as the Naval Air and Missile Test Center, Air Force Western Development Division (WDD) and Space and Missile Systems Organization (SAMSO), and partnership with Aerojet Engineering, enabled it acquire early developmental projects including electronics, instrumentation, ground checkout systems design, and engineering for aircraft, missiles and rocket facilities.
In the early 1950s, Parsons efforts in oil and petrochemical process plants came into focus with design/build efforts supporting both Shell and Gulf Oil in Texas. Parsons delivered systems that would also recover sulfur products for later use in industrial processes. Facilities came on line in 1952.
In 1961, Parsons founded the Ralph M. Parsons Foundation. The foundation became entirely independent from the company in 1974. Also in 1974, Parsons opened the first part of its headquarters in Pasadena.
In 1985, Parsons finalized an Employee Stock Ownership Program (ESOP), allocating shares in proportion to employees’ salaries. The ESOP program continues today.
Parsons interest in bridge projects grew through the 1980s, 1990s, and 2000s leveraging credentials enabled by acquisition of firms including DeLeuw, Cather, and Company in 1977 and Steinman, Boynton, Gronquist and Birdsall (SBGB) in 1988. These acquisitions brought experience and pedigree for design and/or refurbishment of iconic bridge structures including the Mackinac Bridge (Steinman, 1957), Tagus River Bridge, and Brooklyn Bridge. Parsons continues to provide inspection, maintenance, and upgrades for these bridges to this day. The company has also secured numerous design, design-build, and/or construction management jobs delivering new bridges such as the Tacoma Narrows Bridge (2007), John James Audubon Bridge, Windsor-Detroit (Gordie Howe) Bridge, and the Don Welge Memorial Bridge.
In April 1996, Parsons CEO at the time, Leonard Pieroni, was killed in a U.S. Air Force plane crash in the Balkans along with U.S. Commerce Secretary Ron Brown.
In October 2004, Parsons sold its hydrocarbons focused business, Parsons E&C Inc, to Australian firm Worley.
In 2012, Parsons developed the logistics strategy for movement of the Space Shuttle Endeavour from Los Angeles International Airport to the California Science Center near downtown. The effort was completed at no cost to NASA or the science center and was delivered by a team of local consultants that contributed expertise and resources for the effort. The activity brought to a close Parsons support for the Space Shuttle program; efforts that began in 1970 when NASA hired Parsons to perform an independent evaluation of facilities options for the Space Transportation System.
In late February 2019, Parsons announced the move of its headquarters from Pasadena, California to Centreville, Virginia.
On May 8, 2019, Parsons executed an Initial Public Offering of approximately $500 million on the New York Stock Exchange under the symbol PSN. When the transaction was conducted, Parsons returned to public status after leaving 35 years before to become a private, employed-owned company.
On September 1, 2023, Parsons announced the move of its headquarters to Chantilly, VA.
Discussing the company's business outlook in February 2024, CEO Carey Smith stated that the company believes it will continue to see strong demand for its solutions, including cyber, electronic warfare, signals collection, space, missile defense and critical Infrastructure protection given world-wide geopolitical outlook.
In 2025, Parsons Corporation pledged a $2.5 million donation to Donald Trump's demolition of the East Wing of the White House and construction of a White House State Ballroom. The New York Times reported on this donation, noting that the donation came at the same that the Parsons Corporation was jockeying for Trump administration contracts valued for more than $1 trillion.
Controversies
Healthcare centers in Iraq In March 2004, Parsons was awarded a contract for a $243 million project to build 150 healthcare centers in Iraq. By March 2006, $186 million had been spent, with six centers complete and accepted by the U.S. Army Corps of Engineers (USACE), 135 centers partly complete, and one reassigned to another contractor. USACE progressively terminated the contract from September 2005 to March 2006, eventually requiring Parsons to complete a total of 20 centers, with the others to be completed by other contractors. The estimated cost for the completion of the other 121 centers was $36 million. Parsons and USACE disputed the degree to which the final 20 centers were completed. A report by the Special Inspector General for Iraq Reconstruction cited problems, including "high turnover among government personnel... directions... given without agreement from the contractor... program managers' responsiveness to contractor communications, cost and time reporting, administration and quality assurance".
CBOSS positive train control system In November 2011, Parsons was awarded a $138 million contract by the Peninsula Corridor Joint Powers Board (PCJPB), operators of Caltrain system in Northern California. The contract was to design and install communications-based overlay signal system positive train control (CBOSS PTC) as part of the Caltrain Modernization Program. While physical installation had commenced by September 2013, the project missed its 2015 completion deadline. Caltrain contracted a third party review to assess the project; it found program execution issues caused by both parties. By February 2017, although much of the system had been installed (but not fully tested), Caltrain terminated its contract with Parsons for failure to perform, and announced potential litigation. Caltrain then contracted Wabtec to complete the PTC system. Parsons maintained the contract was wrongly terminated and that the delay was beyond its control. Parsons and PCJPB filed lawsuits against each other seeking damages. During early stages of litigation, Parsons and PCJPB agreed that non-performance by subcontractor Alstom substantially caused the delays. With an agreement by Parsons to waive claims against PCJPB and PCJPB agreeing to assign all rights to recovery over to Parsons, they jointly sued Alstom for damages in September 2021. Judgment was reached in September 2024, with Alstom ordered to pay Parsons damages and interest of $135 million for breach of contract. Alstom has appealed the ruling. Wabtec completed the CBOSS PTC installation, employing 80% of the systems delivered by Parsons on the prior contract.
Project timeline 1940s
Less than two months after Parsons was founded, they were hired to provide turnkey engineering, management, and oil well drilling services to the great divide in Colorado, United States.
In 1948, Parsons began work to develop naval missile facilities at Point Mugu Missile facility. Also in 1948, the Atomic Energy Commission created the Idaho National Engineering Laboratory reactor so that it could conduct advanced nuclear experiments with civilian and military reactors. Parsons designed all facilities for test and support operations—including the largest cast-in-place concrete arch ever poured, a span of 3,000 feet.
1950s
In 1952, the U.S. Army awarded Parsons a multi-year design and construction contract role for numerous laboratory and test facilities at the Redstone Arsenal in Huntsville, Alabama.
In January 1953, Parsons began work on the construction of Turkey's first oil refinery near Batman, Turkey.
Between 1957 and 1960, Parsons designed Port Arguello Launch Complex 1 under contract to the U.S. Navy to support the launch of MIDAS and SAMOS programs using Atlas missiles. The facility was renamed Launch Complex 3 when the Air Force assumed control of the base from the Navy.
In 1958, Parsons began fabrication of electronics and instrumentation including miss-distance indicators for the Pershing Medium Range Ballistic Missile. In June 1959, Parsons was awarded a contract for Titan ICBM facility design to be constructed near Moses Lake Washington.
1960s
In 1961, Parsons designed the installation plans for each of the 1,000 Minuteman intercontinental ballistic missiles, which were used by the U.S. Air Force during the Cold War.Howard, William E. Billions for ICBM Launching Facilities // Missiles and Rockets, May 11, 1959, v. 5, no. 19, p.13-14. In 1964, Ralph M. Parsons managed the design of the U.S. Treasury Philadelphia Mint expansion. Parsons created all construction and equipment specifications, oversaw construction, and prepared operations and maintenance manuals.
In 1962, Parsons commenced design efforts as civil architect-engineer for the Titan III Integrate, Transfer, and Launch (ITL) launch complex at Cape Canaveral Air Force Station. Upon completion, the complex became known as Launch Complex 40 and Launch Complex 41. Features of the ITL design included the Vertical Integration Building (VIB) and Solid Rocket Motor Assembly Building (SMAB). The complex supported its first launch in June 1965.
In February 1963, Parsons was contracted to design the Apollo Spacecraft Propulsion System Development Facility at White Sands New Mexico. In 1964, Parsons created a technical and economic blueprint for the North American Water and Power Alliance (NAWAPA), specifically in the United States, Canada and Mexico. The plan outlined concepts to build an integrated system of dams, channels, tunnels, reservoirs, hydroelectric plants, and pumping stations. The plan ultimately did not move forward due to environmental concerns and cost. In 1966, Parsons has served as general engineering consultant for the DC Washington Metro in Washington, D.C., which is a $11 billion, 103-mile rapid transit rail system connecting Washington, D.C., to its many suburbs.
In 1968, Parsons designed and constructed the entire Honolulu Airport in Honolulu, Hawaii (which is now referred to as the Daniel K. Inouye International Airport), including a 12,000-foot runway on an offshore reef to minimize noise in Honolulu. The runway is still used today. In 1968, Parsons began work to upgrade the Federal Aviation Administration (FAA) by providing plans, specifications, and standards to upgrade air traffic controls in 19 facilities. Today, Parsons provides 24/7/365 technical support services in all nine FAA regions and two specialized FAA centers. Again in 2001, Parsons was the prime contractor to implement modernization plans for the national airspace system.
1970s
In 1970, Parsons was hired by BP and ExxonMobil to perform engineering studies in Alaska to determine if the company could overcome the technical and logistical engineering challenges in Arctic oil production. In 1971, Parsons and Union Oil Co. of California demonstrated an improved sulfur recovery process at Union's Los Angeles pilot refinery plant. Based on the proven capacity to extract over 99% of the sulfur contained in the waste gases, the company was contracted to construct a full scale plant to harvest sulfur for industrial uses and reduce pollution.