Dependable Classification of Airports Act This bill allows the owner or operator of a small hub airport that is designated as a medium hub airport to be treated as a small hub airport for a limited period with respect to laws and regulations. (A small hub airport handles 0.05% to 0.25% of the annual U.S. commercial passenger boardings; a medium hub airport handles 0.25% to 1%. Funding opportunities and legal requirements may vary depending on an airport's hub designation.) Specifically, beginning with the fiscal year in which a small hub airport is designated as a medium hub airport, the owner or operator may elect to continue to be treated as a small hub airport for any period of up to five consecutive fiscal years. The bill applies to any small hub airport designated as a medium hub airport in FY2021 or later.