Disaster Contract Transparency Act of 2021 This bill modifies the process for contracting following natural disasters. Specifically, the bill (1) requires state and local governments to have advance contracts in place for debris removal services in order to be eligible for the public assistance grant program; and (2) limits Federal Emergency Management Agency (FEMA) reimbursement of debris removal to the lower of federal, state, or local contract rates. The bill further requires FEMA to penalize vendors for failing to adhere to pre-disaster contracts, develop and implement clear rules regarding the oversight of debris removal contracts, develop a documented risk-based approach for grants that federal coordinating officers can use to determine appropriate cost-effective field presence required for debris removal oversight, and report to Congress annually detailing a comprehensive list of advance contracts and a review of the need for advance contracts that may be lacking for debris removal and other services.