The provisions of the Families First Coronavirus Response Act (FFCRA) providing for emergency paid sick leave and emergency paid family medical leave were set to expire on 12/31/2020. The second stimulus package, signed into law on December 27, 2020, provides for an extension of the payroll tax credits for paid sick and paid family leave through March 31, 2021, however, the law does not extend the required leave provisions. Based on this, it appears that employers will not be required to provide employees with paid sick or family leave after 12/31/2020, however, if they choose to allow employees to take leave for COVID-related reasons, such as when a parent must be home during a school closure and the parent can't work from home, under the FFCRA framework between January 1 and March 31, 2021, they may still claim the payroll tax credit.
See UPDATED DOL Guidance Question #104 - here