COVID-19 Medical Debt Collection Relief Act of 2021 This bill temporarily limits certain activities to collect medical debts by health care providers that apply for, or accept, COVID-19 (i.e., coronavirus 2019) financial relief. Specifically, such health care providers must suspend extraordinary collection actions, such as selling a debt to a third-party collector or placing a lien on an individual's property, until the later of the end of the COVID-19 public health emergency or 18 months after the enactment of this bill. Further, such health care providers must notify individuals who have entered into medical debt repayment plans that they may request the suspension of payments during such period. Providers must provide reasonable repayment options for individuals once repayments resume, such as extending repayment periods. The bill also applies specified consumer protections to medical debt incurred for COVID-19-related testing and treatment between February 1, 2020, and 60 days after the COVID-19 public health emergency ends.