Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2 – S UMMARY OF S IGNIFICANT A CCOUNTING P OLICIES The Company’s significant accounting policies are described in Note 3, Summary of Significant Accounting Policies , to the consolidated financial statements for the year ended December 31, 2021 in the Company’s 2021 Annual Report on Form 10-K. There have been no material changes to the significant accounting policies during the three-month period ended March 31, 2022. Basis of Presentation The accompanying condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and include the accounts of the Company and its wholly owned subsidiary Checkmate Pharmaceuticals Security Corporation. Any reference in these notes to applicable guidance is meant to refer to the authoritative accounting principles generally accepted in the United States as found in the Accounting Standard Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). Unaudited interim financial information The accompanying interim condensed consolidated financial statements and related disclosures are unaudited and have been prepared in accordance with GAAP for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X of the Exchange Act. Accordingly, they do not include all the information and footnotes required by GAAP for complete consolidated financial statements and should be read in conjunction with the Company’s consolidated financial statements and related footnotes as of and for the year ended December 31, 2021, included in the Company’s 2021 Annual Report on Form 10-K. The Company’s financial information as of March 31, 2022, and for the three months ended March 31, 2022 and 2021 is unaudited, but in the opinion of management, includes all adjustments, consisting only of normal recurring adjustments, considered necessary for a fair presentation of the financial position, results of operations and cash flows at the dates and for the periods presented. The balance sheet data as of December 31, 2021 was derived from audited consolidated financial statements. The results of the Company’s operations for any interim period are not necessarily indicative of the results that may be expected for any other interim period or for a full fiscal year. Use of estimates The preparation of the Company’s condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of stock-based awards. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results may differ from those estimates or assumptions. Recently issued accounting pronouncements In June 2016, the FASB issued ASU 2016-13, “Credit Losses (Topic 326).” ASU 2016-13 requires that financial assets measured at amortized cost, such as trade receivables and investments, be represented net of expected credit losses, which may be estimated based on relevant information such as historical experience, current conditions, and future expectation for each pool of similar financial asset. The new guidance requires enhanced disclosures related to trade receivables and associated credit losses. In May 2019, the FASB issued ASU No. 2019-05, “Financial Instruments—Credit Losses (Topic 326) Targeted Transition Relief,” which allows for a transition election on certain instruments. The guidance is effective for Smaller Reporting Companies for fiscal years beginning after December 15, 2022 and interim periods in those fiscal years. In November 2019, the FASB issued ASU No. 2019-11 which amends certain aspects of ASU No. 2016-13, including transition relief for trouble debt restructuring, among other topics. The Company is currently evaluating the impact of this pronouncement on its condensed consolidated financial statements.

Checkmate Pharmaceuticals, Inc. 10-Q