Results of Operations and Financial Condition. On July 29, 2026, Parson Corporation (the “Company”) issued a press release announcing its financial results for the quarter ended June 30, 2026 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

Results of Operations and Financial Condition. On April 29, 2026, Parson Corporation (the “Company”) issued a press release announcing its financial results for the quarter ended March 31, 2026 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

CHRO — Susan Balaguer: Susan Balaguer, the CHRO, announced her retirement with a transition period.

The filing describes a compensatory stock award to the CEO, not a management change.

Results of Operations and Financial Condition. On February 11, 2026, Parson Corporation (the “Company”) issued a press release announcing its financial results for the year ended December 31, 2025 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

Other Events. On January 15, 2026, Parsons Corporation announced the signing and closing of a Stock Purchase Agreement for the acquisition of Altamira Technologies Corporation by Parsons Government Service, Inc. A copy of the press release is attached hereto.

CLO — Michael R. Kolloway: The filing discloses the retirement of the Chief Legal Officer and the appointment of a named external successor, representing an orderly succession rather than a sudden loss of leadership.

Director — Robert H. Smith: The filing discloses the appointment of a new director to the board, which is a routine governance event and not a departure of a senior executive.

Results of Operations and Financial Condition. On November 5, 2025, Parson Corporation (the “Company”) issued a press release announcing its financial results for the quarter ended September 30, 2025 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

Results of Operations and Financial Condition. On August 6, 2025, Parson Corporation (the “Company”) issued a press release announcing its financial results for the quarter ended June 30, 2025 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

Termination of Material Definitive Agreement. The disclosure required by this item regarding the termination of prior credit facilities is included in

Entry into a Material Definitive Agreement. Summary: The Company has refinanced its existing term loan and revolving credit facility which matured October 2025 and June 2026, respectively. Details of the transaction are below. On June 5, 2025 (the “ Closing Date ”), the Company entered into a $450,000,000 unsecured term loan credit facility with an increase option of up to $150,000,000 (“ 2025 Term Loan ”) evidenced by an unsecured term loan credit agreement (the “ 2025 Term Loan Agreement ”)…

Results of Operations and Financial Condition. On April 30, 2025, Parson Corporation (the “Company”) issued a press release announcing its financial results for the quarter ended March 31, 2025 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

Other Events. On March 20, 2025, the Company’s board of directors approved increasing the Company’s stock repurchase authority to $250 million. There can be no assurance of repurchases, as they depend upon a variety of factors, including changes in market conditions and economic circumstances, availability of investment opportunities, uncertainties relating to availability and costs of our financing needs in the future, currency fluctuations, the market price of the Company’s common stock and…

Results of Operations and Financial Condition. On February 19, 2025, Parson Corporation (the “Company”) issued a press release announcing its financial results for the year ended December 31, 2024 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

Results of Operations and Financial Condition. On October 30, 2024, Parson Corporation (the “Company”) issued a press release announcing its financial results for the quarter ended September 30, 2024 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

Results of Operations and Financial Condition. On July 31, 2024, Parson Corporation (the “Company”) issued a press release announcing its financial results for the quarter ended June 30, 2024 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1

Results of Operations and Financial Condition. On May 1, 2024, Parson Corporation (the “Company”) issued a press release announcing its financial results for the quarter ended March 31, 2024 and certain other financial information. A copy of the press release is attached to this Form 8-K as Exhibit 99.1