Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2015
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	Note 1 – Summary of Significant Accounting Policies The accounting policies followed in the preparation of the interim consolidated financial statements are consistent with those used in the preparation of the annual financial information. The interim consolidated financial statements reflect all normal and recurring adjustments, which are necessary, in the opinion of management, for a fair statement of results for the interim period presented. Results for the period ended March 31, 2015, are not necessarily indicative of the results that may be expected for the year ending December 31, 2015. These interim consolidated financial statements are unaudited and should be read in conjunction with the audited financial statements and notes included in Old Second Bancorp, Inc.’s (the “Company”) annual report on Form 10-K for the year ended December 31, 2014. Unless otherwise indicated, amounts in the tables contained in the notes to the consolidated financial statements are in thousands. Certain items in prior periods have been reclassified to conform to the current presentation. The Company’s consolidated financial statements are prepared in accordance with United States generally accepted accounting principles (“GAAP”) and follow general practices within the banking industry. Application of these principles requires management to make estimates, assumptions, and judgments that affect the amounts reported in the consolidated financial statements and accompanying notes. These estimates, assumptions, and judgments are based on information available as of the date of the consolidated financial statements. Future changes in information may affect these estimates, assumptions, and judgments, which, in turn, may affect amounts reported in the consolidated financial statements. All significant accounting policies are presented in Note 1 to the consolidated financial statements included in the Company’s annual report on Form 10-K for the year ended December 31, 2014. These policies, along with the disclosures presented in the other financial statement notes and in this discussion, provide information on how significant assets and liabilities are valued in the consolidated financial statements and how those values are determined. Recent Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09 "Revenue from Contracts with Customers (Topic 606)." The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The amendments can be applied retrospectively to each prior reporting period or retrospectively with the cumulative effect of initially applying this update recognized at the date of initial application. Early application is not permitted. The Company is assessing the impact of ASU 2014-09 on its accounting and disclosures. On April 1, 2015, the FASB voted to propose a delay in the effective date of ASU 2014 – 09. On April 29, 2015, FASB issued a proposed accounting standards update to defer the effective date of an additional year. If the proposal is approved, the standard will be effective for annual reporting periods beginning after December 15, 2017. FASB requested comments on the proposal by May 29, 2015.

Note 1 – Summary of Significant Accounting Policies

The accounting policies followed in the preparation of the interim consolidated financial statements are consistent with those used in the preparation of the annual financial information. The interim consolidated financial statements reflect all normal and recurring adjustments, which are necessary, in the opinion of management, for a fair statement of results for the interim period presented. Results for the period ended March 31, 2015, are not necessarily indicative of the results that may be expected for the year ending December 31, 2015. These interim consolidated financial statements are unaudited and should be read in conjunction with the audited financial statements and notes included in Old Second Bancorp, Inc.’s (the “Company”) annual report on Form 10-K for the year ended December 31, 2014. Unless otherwise indicated, amounts in the tables contained in the notes to the consolidated financial statements are in thousands. Certain items in prior periods have been reclassified to conform to the current presentation.

The Company’s consolidated financial statements are prepared in accordance with United States generally accepted accounting principles (“GAAP”) and follow general practices within the banking industry. Application of these principles requires management to make estimates, assumptions, and judgments that affect the amounts reported in the consolidated financial statements and accompanying notes. These estimates, assumptions, and judgments are based on information available as of the date of the consolidated financial statements. Future changes in information may affect these estimates, assumptions, and judgments, which, in turn, may affect amounts reported in the consolidated financial statements.

All significant accounting policies are presented in Note 1 to the consolidated financial statements included in the Company’s annual report on Form 10-K for the year ended December 31, 2014. These policies, along with the disclosures presented in the other financial statement notes and in this discussion, provide information on how significant assets and liabilities are valued in the consolidated financial statements and how those values are determined.

Recent Accounting Pronouncements

In May 2014, the FASB issued ASU No. 2014-09 "Revenue from Contracts with Customers (Topic 606)." The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The amendments can be applied retrospectively to each prior reporting period or retrospectively with the cumulative effect of initially applying this update recognized at the date of initial application. Early application is not permitted. The Company is assessing the impact of ASU 2014-09 on its accounting and disclosures. On April 1, 2015, the FASB voted to propose a delay in the effective date of ASU 2014 – 09. On April 29, 2015, FASB issued a proposed accounting standards update to defer the effective date of an additional year. If the proposal is approved, the standard will be effective for annual reporting periods beginning after December 15, 2017. FASB requested comments on the proposal by May 29, 2015.