Medical Supply Chain Emergency Act of 2020 This bill directs the President to use existing authorities under the Defense Production Act of 1950 with respect to the production of ventilators, N-95 respirator masks, and specified personal protective equipment to address COVID-19 (i.e., coronavirus disease 2019). (That act confers upon the President a broad set of authorities to influence domestic industry in order to provide essential materials and goods needed for the national defense.) The President must (1) make a determination that such items are essential for the national defense, (2) identify private-sector capacity to produce these items, and (3) exercise authorities under the act to require emergency production of them at a reasonable price. In addition, the President shall coordinate the allocation of these items based on requests from governors and the needs of the states as determined by the number of COVID-19 cases and the proportion of the population at higher risk of the disease in a given state. The bill makes specified funds available for these efforts. Equipment produced under these authorities but unused at the termination of the COVID-19 emergency declared on March 13, 2020, shall be deposited into the Strategic National Stockpile.