PurposeThe authors investigate how managers adapt their financial reporting and disclosure practices in response to the COVID-19 pandemic through changes in accounting estimates (CAEs).Design/methodology/approachThe authors define the pandemic period as starting on March 1, 2020. The sample consists of 9,575 CAEs disclosed in quarterly (10-Qs) and annual (10-Ks) financial reports by US firms between January 1, 2004 and May 31, 2022. The authors perform multivariate analyses of the impact of the COVID-19 pandemic on the incidence of CAEs and on whether the impact of CAEs on firms' financial performance and reporting quality changes during the pandemic.FindingsIn the examination of the CAE footnote disclosures in the quarterly (10-Qs) and annual (10-Ks) reports of US companies, the authors find no evidence that the incidence of CAEs in 10-Ks or the number of firms reporting CAEs are significantly different in the pre-pandemic and pandemic periods, but the incidence of CAEs in 10-Qs is significantly higher in the pandemic period than in the pre-pandemic period. The authors also find that the number of CAEs related to revenue recognition increase significantly in the pandemic period, but CAEs in other categories decrease, with the sharpest drop seen in the liabilities category. Further investigation suggests that although the dollar impact of 10-K CAEs on current financial statements is higher during the pandemic period, firms with CAEs, especially positive CAEs, in either 10-Ks or 10-Qs are less likely to use CAEs to boost earnings in the pandemic period. However, the authors find evidence that firms tend to use CAEs to “big bath” current earnings and create reserve for future period. The authors have not observed any significant differences in how the various phases of the pandemic affect the reporting of CAEs. Additionally, there is no evidence to suggest that financially distressed firms report more or fewer CAEs during the pandemic.Practical implicationsThe results are consistent with the notion that, during the pandemic, firms exercise greater caution in their CAE disclosures, refraining from using CAEs as a means of boosting earnings but as a strategy to create reserve for future period. The paper highlights the challenges that various stakeholders face when assessing a company's current and future financial performance based on management's accounting estimates.Originality/valueThis study captures the impact of the COVID-19 pandemic on the incidence of CAEs and CAEs' impact on the financial performance and financial reporting quality of firms during the pandemic.