"The Taxpayer Certainty and Disaster Tax Relief Act of 2020, enacted December 27, 2020, made a number of changes to the employee retention tax credits previously made available under the Coronavirus Aid, Relief, and Economic Security Act (CARES Act), including modifying and extending the Employee Retention Credit (ERC), for six months through June 30, 2021. Several of the changes apply only to 2021, while others apply to both 2020 and 2021."