Lower Drug Costs for Seniors During COVID-19 Act of 2020 This bill requires the Centers for Medicare & Medicaid Services to establish a process for prescription drug plans under Medicare and Medicare Advantage to allow enrollees to make coinsurance payments in periodic installments, if the enrollee chooses to obtain the entire prescribed supply of a covered drug in a single fill. Current law allows an enrollee, during the public health emergency relating to COVID-19 (i.e., coronavirus disease 2019), to obtain the entire prescribed supply of a covered drug in a single fill or refill, up to a 90-day supply.