Medicare Accelerated and Advance Payments Improvement Act This bill establishes and otherwise modifies requirements for the Medicare Accelerated and Advance Payment Program during the public health emergency relating to COVID-19 (i.e., coronavirus disease 2019). The program provides Medicare payments in advance to eligible providers experiencing claims or cash flow disruptions, such as during national emergencies; the program was specifically expanded in response to COVID-19 to encompass more types of providers, subject to certain recoupment and repayment provisions. Under the current program, recoupment of advance payments (through claims offsets) begins up to four months after the payment is made. Additionally, certain hospitals have one year to repay the full amount; other types of providers have seven months. Repayments made after this period are subject to the prevailing interest rate set by the Department of the Treasury (generally around 10% in FY2020). The bill delays recoupment for one year and caps the recoupment at 25% of a claim. The bill also gives all providers up to two years for full repayment and caps the interest rate at 1%. Additionally, the Centers for Medicare & Medicaid Services (CMS) may waive repayment entirely upon a demonstration of extreme hardship, among other factors. The bill also requires the CMS to continue to make the program available to providers of Medicare medical services for the duration of the public health emergency. (The CMS suspended the program for such providers on April 26, 2020.)