ComEd 2006 Annual Report Download - page 155

Report of Independent Registered Public Accounting Firm
To The Shareholders and Board of Directors of Exelon Corporation:
We have completed integrated audits of Exelon Corporation’s consolidated financial statements and of
its internal control over financial reporting as of December 31, 2006, in accordance with the standards
of the Public Company Accounting Oversight Board (United States). Our opinions, based on our audits,
are presented below.
Consolidated financial statements and financial statement schedule
In our opinion, the consolidated financial statements listed in the index appearing under Item 15(a)(1)(i)
present fairly, in all material respects, the financial position of Exelon Corporation and its subsidiaries
at December 31, 2006 and 2005, and the results of their operations and their cash flows for each of the
three years in the period ended December 31, 2006 in conformity with accounting principles generally
accepted in the United States of America. In addition, in our opinion, the financial statement schedule
listed in the index appearing under Item 15(a)(1)(ii) presents fairly, in all material respects, the
information set forth therein when read in conjunction with the related consolidated financial
statements. These financial statements and financial statement schedule are the responsibility of the
Company’s management. Our responsibility is to express an opinion on these financial statements and
financial statement schedule based on our audits. We conducted our audits of these statements in
accordance with the standards of the Public Company Accounting Oversight Board (United States).
Those standards require that we plan and perform the audit to obtain reasonable assurance about
whether the financial statements are free of material misstatement. An audit of financial statements
includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial
statements, assessing the accounting principles used and significant estimates made by management,
and evaluating the overall financial statement presentation. We believe that our audits provide a
reasonable basis for our opinion.
As discussed in Note 1 to the consolidated financial statements, Exelon Corporation changed its
method of accounting for conditional asset retirement obligations as of December 31, 2005, its method
of accounting for stock-based compensation as of January 1, 2006, and its method of accounting for its
defined benefit pension and other postretirement plans as of December 31, 2006.
Internal control over financial reporting
Also, in our opinion, management’s assessment, included in Management's Report on Internal Control
Over Financial Reporting appearing under Item 8, that the Company maintained effective internal
control over financial reporting as of December 31, 2006 based on criteria established in Internal
Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the
Treadway Commission (COSO), is fairly stated, in all material respects, based on those criteria.
Furthermore, in our opinion, the Company maintained, in all material respects, effective internal control
over financial reporting as of December 31, 2006, based on criteria established in Internal Control—
Integrated Framework issued by the COSO. The Company’s management is responsible for
maintaining effective internal control over financial reporting and for its assessment of the effectiveness
of internal control over financial reporting. Our responsibility is to express opinions on management’s
assessment and on the effectiveness of the Company’s internal control over financial reporting based
on our audit. We conducted our audit of internal control over financial reporting in accordance with the
standards of the Public Company Accounting Oversight Board (United States). Those standards
require that we plan and perform the audit to obtain reasonable assurance about whether effective
internal control over financial reporting was maintained in all material respects. An audit of internal
control over financial reporting includes obtaining an understanding of internal control over financial
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