Keeping School Meals Flexible Act This bill extends authority through June 30, 2023, for the Department of Agriculture (USDA) to waive certain requirements for the school meal programs to address COVID-19. The bill extends the authority for USDA to issue a single waiver of child nutrition program requirements to all states under the National School Lunch Program for purposes of providing meals and snacks with appropriate safety measures with respect to COVID-19; grant waivers of requirements to allow non-congregate feeding in the Child and Adult Care Food Program for purposes of providing meals and snacks with appropriate safety measures with respect to COVID-19; and grant waivers related to the nutritional content of meals served in child nutrition programs if it determines the waiver is necessary to provide meals and snacks, and there is a food supply chain disruption due to COVID-19.