Emergency Supplemental Appropriations for Disaster Relief and Puerto Rico Disaster Tax Relief Act, 2020 This bill provides FY2020 supplemental appropriations and expands tax credits to respond to recent natural disasters and emergencies that affected Puerto Rico and other U.S. territories. The funding provided by this bill is designated as emergency spending, which is exempt from discretionary spending limits. The bill provides $4.89 billion in FY2020 supplemental appropriations for programs within the Department of Energy, the Department of Education, the Federal Highway Administration, the Department of Housing and Urban Development, and the Department of Agriculture. The programs address issues such as cybersecurity, energy security, and emergency response; the electric grid; the educational needs of individuals affected by natural disasters and emergencies; repairs to roads affected by natural disasters and emergencies; community development; and disaster nutrition assistance. The bill also expands tax credits and modifies related requirements that affect the residents of Puerto Rico and other U.S. territories. The bill includes provisions regarding the child tax credit, the earned income tax credit, the low-income housing tax credit, the new markets tax credit, the amount of distilled spirits excise taxes covered over (paid) to the treasuries of Puerto Rico and the Virgin Islands, and an employee retention tax credit.