AMERICAN TOWER CORP MA

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Stockholders and the Board of Directors of American Tower Corporation

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of American Tower Corporation and subsidiaries (the “Company”) as of December 31, 2023 and 2022, the related consolidated statements of operations, comprehensive income, equity, and cash flows, for each of the three years in the period ended December 31, 2023, and the related notes and the schedule listed in the Index at Item 15 (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 27, 2024, expressed an unqualified opinion on the Company's internal control over financial reporting.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the 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 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 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 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 financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the 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.

Determination of fair value of the Spain reporting unit - Refer to Notes 1, 5, 11, and 16 to the financial statements.

Critical Audit Matter Description

The Company reviews goodwill for impairment at least annually or whenever events or circumstances indicate the carrying value of an asset may not be recoverable. The Company’s evaluation of recovery of goodwill involves the comparison of the carrying amount of a reporting unit, inclusive of allocated goodwill, to the fair value of the applicable reporting unit. If goodwill is determined to be impaired, the amount of impairment recognized is the amount by which the carrying amount of the reporting unit exceeds the fair value of the reporting unit. Fair value is generally determined using discounted forecasted cash flows.

The Company performed its annual impairment test as of December 31, 2023 for the Spain reporting unit. The resulting fair value was compared to the reporting unit’s carrying amount, which indicated that the carrying amount exceeded the estimated fair value. Accordingly, the Company recorded an impairment charge of $80.0 million in the consolidated statement of operations. The remaining goodwill allocated to the Spain reporting unit as of December 31, 2023 was $737.6 million.

We identified the determination of the fair value of the Spain reporting unit, along with the resulting impairment charge, as a critical audit matter due to the significant judgments made by management to estimate the fair value of the reporting unit. There was a high degree of auditor judgment in evaluating management’s assumptions and estimates related to revenue growth rate, margin projections, and discount rate used in the determination of fair value based upon a discounted cash flow model.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to the determination of fair value of the Spain reporting unit and the recording of a goodwill impairment charge included the following, among others:

•We tested the effectiveness of internal controls over management’s goodwill impairment evaluation, including those over the determination of the fair value of the Spain reporting unit.

•We evaluated the reasonableness of management’s future contracted revenue, revenue growth rates, and margin projections used in the discounted cash flow model to:

◦Historical results.

◦Internal communications to management and the Board of Directors and external communications to investors.

◦Forecasted information included in analyst and industry reports for the Company and the Spanish market.

•With the assistance of our business valuation specialists, we evaluated the reasonableness of the discount rate used in the discounted cash flow model.

•We recalculated the carrying amount of the reporting unit.

•We reperformed the comparison of the fair value to the carrying amount and recalculated the amount of the resulting impairment charge.

/s/Deloitte & Touche LLP

Boston, Massachusetts

February 27, 2024

We have served as the Company’s auditor since 1997.