Having Employees Return to Duty Act or the HERD Act This bill addresses federal employees who comply with Executive Order 14043 (requiring COVID-19 vaccination for federal employees). Specifically, the bill requires each federal agency to require employees who comply with the order to work from their duty station and to work the hours required as of February 15, 2020. The bill's requirement does not apply to immunocompromised employees. Additionally, the bill does not prohibit an agency from implementing different policies at a particular work site if the agency finds that (1) there is substantial transmission of COVID-19 within a community in which such requirements would otherwise be carried out; and (2) implementing those different policies will not degrade the level of service that the agency provides to the public.