Health Heroes 2020 Act This bill appropriates funds for, and makes other changes to, scholarship and loan repayment programs for health care providers who agree to a period of obligated service in a health professional shortage area. Specifically, the bill provides funds through FY2026 for the National Health Service Corps and otherwise modifies the program, including by (1) authorizing the Department of Health and Human Services (HHS), subject to certain limitations, to reassign corps members to alternative sites during a declared public health emergency; and (2) establishing a demonstration project that allows corps members to fulfill their service obligations through a period of reserve status, during which HHS may deploy them to respond to a declared emergency. The bill also provides FY2020 funds for the Nurse Corps scholarship and loan repayment programs. These funds are designated as an emergency requirement, which exempts the funds from discretionary spending limits and other budget enforcement rules.