COLUMBIA ALLIED SERVICES INC.

le U.S. employees who are not provided retirement benefits through a collective bargaining agreement may make contributions through payroll deductions and to which we make certain matching contributions. Ethics and Compliance All of our employees are subject to Quanta’s Code of Conduct, which addresses compliance with applicable laws and Quanta’s policies concerning, among other things, general business ethics, competition, anti-corruption and bribery, environmental protection, conflicts of interest, harassment and discrimination, data security and privacy, and insider trading. Quanta’s Code of Conduct also informs employees and third parties (such as suppliers, subcontractors and members of the public) about the resources and confidential reporting mechanisms available to detect, prevent

law. Quanta may also make discretionary employer contributions to such plan. Matching contributions vest immediately, and discretionary employer contributions may be subject to a vesting schedule determined at the time of the contribution, provided that vesting accelerates upon a change in control or the participant’s death or retirement. All matching and discretionary employer contributions, whether vested or not, are forfeited upon a participant’s termination of employment for cause or upon the participant engaging in competition with Quanta or any of its affiliates. As of December 31, 2025 and 2024, the liability related to deferred cash compensation under these plans, including amounts contributed by Quanta, was $ 126.1 million and $ 110.2 million, the majority of which was included i

2 20.1 % Gross profit 4,275,081 15.0 3,510,761 14.8 764,320 21.8 % Equity in earnings of integral unconsolidated affiliates 55,635 0.2 50,484 0.2 5,151 10.2 % Selling, general and administrative expenses (2,189,209) (7.7) (1,824,754) (7.7) (364,455) 20.0 % Amortization of intangible assets (498,795) (1.7) (382,959) (1.6) (115,836) 30.2 % Increase in fair value of contingent consideration liabilities (31,203) (0.1) (7,064) — (24,139) 341.7 % Operating income 1,611,509 5.7 1,346,468 5.7 265,041 19.7 % Interest and other financing expenses (261,445) (1.0) (202,687) (0.9) (58,758) 29.0 % Interest income 15,702 0.1 32,404 0.1 (16,702) (51.5) % Other income, net 23,739 0.1 35,845 0.2 (12,106) (33.8) % Income before income taxes 1,389,505 4.9 1,212,030 5.1 177,475 14.6 % Provision for income taxe

ns. Participants who have attained age 50 before the end of the Plan year are eligible to make catch-up contributions. Employer match – The Company may elect to make discretionary matching contributions to the Plan. Matching contributions are made each pay period. The Company matched 50 % of employee contributions, up to 8 % of eligible compensation deferred to the Plan for the year ended December 31, 2025. Employer profit sharing – The Company may elect to make discretionary profit sharing contributions to the Plan. Participants must complete at least 1,000 hours of service during the Plan year and be employed as of the last day of the Plan year, to be eligible to receive any profit sharing contributions. Profit sharing contributions are allocated to participants in the same proportion as

G PLAN NOTES TO FINANCIAL STATEMENTS AS OF DECEMBER 31, 2025 AND 2024, AND FOR THE YEAR ENDED DECEMBER 31, 2025 Note 1 – Description of Plan (continued) Vesting – Participants are fully vested at all times in that portion of their accounts attributable to their own contributions and earnings or losses thereon. Vesting in Company contributions is based on years of service pursuant to the following vesting schedule. Participants who were part of acquired plans may have specific vesting schedules in accordance with those plans. Years of service Percentage Less than 1 year — % 1 year but less than 2 20 % 2 years but less than 3 40 % 3 years but less than 4 60 % 4 years but less than 5 80 % 5 years or more 100 % Notes receivable from participants – Participants may borrow from their accounts a

signated as independent contractors, are eligible to participate in the 401(k) portion of the Plan upon reaching age 18. Once the eligibility criteria have been met, employees are automatically enrolled into the Plan at a deferral rate of 6 % of their eligible compensation, unless they choose to opt-out. Employees enter the Plan on scheduled enrollment dates following their completion of the eligibility requirements. Contributions – Contributions are subject to regulatory limitations. Employee deferrals – Participants may elect to contribute up to 80 % of eligible compensation. In addition, participants may make voluntary Roth after-tax contributions or voluntary non-deductible after-tax contributions to the Plan. Participants may also roll over eligible amounts from other qualified plans.

37,765 Rollovers 9,637 Total contributions 60,844 Total additions 180,848 DEDUCTIONS FROM NET ASSETS ATTRIBUTED TO Benefits paid to participants 91,654 Corrective distributions 26 Administrative expenses 607 Total deductions 92,287 CHANGE IN NET ASSETS 88,561 NET ASSETS AVAILABLE FOR BENEFITS Beginning of year 761,328 End of year $ 849,889 See accompanying notes. 4 COLUMBIA BANK 401(k) AND PROFIT SHARING PLAN NOTES TO FINANCIAL STATEMENTS AS OF DECEMBER 31, 2025 AND 2024, AND FOR THE YEAR ENDED DECEMBER 31, 2025 Note 1 – Description of Plan The following description of the Columbia Bank 401(k) and Profit Sharing Plan (the "Plan") provides only general information. Participants should refer to the Plan Agreement, as amended, for a more complete description of Plan provisions. Effective Sept