MASTEC INC

To the Board of Directors and Shareholders of MasTec, Inc.

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated balance sheet of MasTec, Inc. and its subsidiaries (the “Company”) as of December 31, 2024, and the related consolidated statements of operations, comprehensive income (loss), equity and cash flows for the year then ended, including the related notes and schedule of valuation and qualifying accounts for the year ended December 31, 2024 appearing after Item 16 (collectively referred to as the “consolidated financial statements”). We also have audited the Company's internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2024, and the results of its operations and its cash flows for the year then ended, in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO.

Basis for Opinions

The Company's management is responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in Management's Report on Internal Control Over Financial Reporting appearing under Item 9A. Our responsibility is to express opinions on the Company’s consolidated financial statements and on the Company's internal control over financial reporting based on our audit. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects.

Our audit of the consolidated financial statements included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audit also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audit also included performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinions.

As described in Management’s Report on Internal Control Over Financial Reporting, management has excluded two entities (related to a July acquisition in the Power Delivery segment and a December acquisition in the Pipeline Infrastructure segment) from its assessment of internal control over financial reporting as of December 31, 2024 because they were acquired by the Company in purchase business combinations during 2024. We have also excluded the two entities from our audit of internal control over financial reporting. The two entities’ total assets and total revenues excluded from management’s assessment and our audit of internal control over financial reporting collectively represent approximately 2% and less than 1%, respectively, of the related consolidated financial statement amounts as of and for the year ended December 31, 2024.

Definition and Limitations of Internal Control over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Critical Audit Matters

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Revenue Recognition – Determination of Estimated Costs to Complete Certain Contracts Recognized Over Time

The Company recognized revenue of $12.3 billion for the year ended December 31, 2024, of which a majority relates to revenue recognized from contracts for specific projects requiring the construction and installation of an entire infrastructure system, or specified units within an infrastructure system. As described in Note 1 to the consolidated financial statements, revenue related to these contracts is recognized over time using the cost-to-cost measure of progress, which is an input method. Contract costs include all direct materials, equipment, labor and subcontracted costs related to contract performance. The cost estimation processes used for recognizing revenue over time under the cost-to-cost method require management to make significant assumptions and judgments, based primarily on the professional knowledge and experience of the Company’s project managers, operational and financial professionals. Changes in job performance and job conditions are factors that influence estimates of the total costs to complete those contracts. Changes in these factors that result in revisions to the amount of revenue recognized for a given project are recognized in the period in which the revisions are determined.

The principal considerations for our determination that performing procedures relating to revenue recognition, specifically the determination of estimated costs to complete certain contracts recognized over time, is a critical audit matter are (i) the significant judgment by management in determining the estimated contract costs to complete certain contracts recognized over time; and (ii) a high degree of auditor judgment, subjectivity, and effort in performing procedures and evaluating audit evidence related to management’s estimate of costs to complete certain contracts recognized over time.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of controls relating to the revenue recognition process, including controls related to the determination of estimated costs to complete certain contracts recognized over time. These procedures also included, among others, for a sample of contracts, (i) testing management’s process for determining the estimated contract costs to complete; (ii) testing the completeness and accuracy of underlying data used by management related to actual costs to date; and (iii) evaluating the reasonableness of certain significant judgments and assumptions considered by management specific to each contract. Evaluating the significant judgments and assumptions related to estimated contract costs to complete involved evaluating whether the significant judgments and assumptions used by management were reasonable, considering (i) the terms of the contracts and other documents that support those estimates; (ii) actual costs to date to assess the reasonableness of the estimate of the remaining costs to complete; (iii) management’s ability to reasonably estimate costs to complete by performing a comparison of the total estimated contract costs as compared with prior period estimates, including evaluating the timely identification of circumstances that may warrant a modification to the estimated contract costs to complete; and (iv) evaluating management’s methodologies and the consistency of management’s methodologies over the lives of contracts.

/s/PricewaterhouseCoopers LLP

Miami, Florida

February 28, 2025

We have served as the Company’s auditor since 2024.

Shareholders and Board of Directors

MasTec, Inc.

Coral Gables, Florida

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheet of MasTec, Inc. (the “Company”) as of December 31, 2023, the related consolidated statements of operations and comprehensive income, equity, and cash flows for each of the two years in the period ended December 31, 2023, and the related notes and financial statement schedule listed in the accompanying index (collectively referred to as the “consolidated financial statements”). In our opinion, based on our audits and the report of the other auditors, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2023, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America.

We did not audit the financial statements of IEA Energy Services, LLC and subsidiaries (“IEA LLC”), a wholly-owned subsidiary of the Company, which statements reflect total assets of $686.6 million at December 31, 2023, and total revenues of $1,732.1 million for the year then ended. Those statements were audited by other auditors whose report has been furnished to us, and our opinion, insofar as it relates to the amounts included for IEA LLC, is based solely on the report of the other auditors.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits and the report of the other auditors provide a reasonable basis for our opinion.

/s/BDO USA, P.C.

We served as the Company’s auditor from 2004 to 2024.

Miami, Florida

February 29, 2024, except for Note 13, as to which the date is February 28, 2025

To the shareholders and the Board of Directors of MasTec, Inc.

Opinion on the Financial Statements

We have audited the consolidated balance sheet of IEA Energy Services, LLC and its consolidated subsidiaries (“IEA LLC”) as of December 31, 2023, the related consolidated statement of operations, members’ equity (deficit), and cash flows, for the year ended December 31, 2023, and the related notes (collectively referred to as the "financial statements" and not presented herein).

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of IEA LLC as of December 31, 2023, and the results of its operations and its cash flows for the year ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

IEA LLC’s management is responsible for these financial statements. Our responsibility is to express an opinion on these financial statements based on our audit. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to IEA LLC in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB and in accordance with auditing standards generally accepted in the United States of America. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud.

Our audit of the financial statements included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures to respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audit also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audit provides a reasonable basis for our opinion.

Other Matter

As discussed in Note 10 to the IEA LLC financial statements, IEA LLC engages in significant transactions with affiliates such as MasTec, Inc. and Infrastructure and Energy Alternatives, Inc. Portions of certain income and expenses represent allocations made from affiliates for items applicable to IEA LLC as a whole. Therefore, the financial statements of IEA LLC have been prepared from the separate records maintained by IEA LLC and its parent and may not be indicative of the conditions that would have existed or the results of operations if IEA LLC had been operated as an unaffiliated company.

/s/Deloitte & Touche LLP

Indianapolis, Indiana

February 29, 2024

We began serving as IEA LLC’s auditor in 2018. In 2024 we became the predecessor auditor.