Global COVID-19 Truth, Transparency, and Accountability Act This bill requires assessments of the response of the World Health Organization (WHO) to the COVID-19 (i.e., coronavirus disease 2019) pandemic. The Department of State shall report to Congress on the effectiveness, transparency, and accountability of the WHO's response to the COVID-19 pandemic, including an assessment of information about the pandemic that China conveyed to or withheld from the WHO. The report shall assess whether WHO regulations need to be updated and whether new mechanisms are needed to effectively address pandemics and increase accountability. Materials submitted in support of the President's annual budget shall include an assessment of (1) whether institutional reforms at the WHO are needed to ensure accountability and effectiveness, and (2) whether U.S. contributions to the WHO should be withheld in the absence of such reforms.