Report Of Independent Registered Public Accounting Firm The Board of Directors and Shareholders  Morningstar, Inc. We have audited Morningstar, Inc. and subsidiaries’ internal control  over financial reporting as of December 31, 2010, based on criteria  established in Internal Control—Integrated Framework issued by  the Committee of Sponsoring Organizations of the Treadway  Commission (the COSO criteria). Morningstar, Inc. and subsidiaries’  management is responsible for maintaining effective internal con- trol over financial reporting, and for its assessment of the effective- ness of internal control over financial reporting included in the  accompanying Management’s Report on Internal Control Over  Financial Reporting. Our responsibility is to express an opinion on the  company’s internal control over financial reporting based on our audit. We conducted our audit 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. Our  audit included obtaining an understanding of internal control over  financial reporting, assessing the risk that a material weakness  exists, testing and evaluating the design and operating effectiveness  of internal control based on the assessed risk, and performing such  other procedures as we considered necessary in the circumstances.  We believe that our audit provides a reasonable basis for our opinion. 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 account- ing principles. A company’s internal control over financial reporting  includes those policies and procedures that (1) pertain to the main- tenance of records that, in reasonable detail, accurately and fairly  reflect the transactions and dispositions of the assets of the com- pany; (2) 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 (3) provide reasonable assurance regarding pre- vention 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. In our opinion, Morningstar, Inc. and subsidiaries maintained, in all  material respects, effective internal control over financial reporting  as of December 31, 2010, based on the COSO criteria. We also have audited, in accordance with the standards of the  Public Company Accounting Oversight Board (United States), the  consolidated balance sheets of Morningstar, Inc. and subsidiaries  as of December 31, 2010 and 2009, and the related consolidated  statements of income, equity and comprehensive income (loss), and  cash flows for each of the three years in the period ended December  31, 2010 of Morningstar, Inc. and subsidiaries and our report dated  February 28, 2011 expressed an unqualified opinion thereon. /s/ Ernst & Young LLP Chicago, IL February 28, 2011 Morningstar, Inc. 2010 Annual Report 99