Q:   What constitutes an overpayment under CMS guidelines? Since overpayments should be returned within sixty (60) days, when does the 60 day clock start? A:   In the final rule published Feb. 12, 2016, the Centers for Medicare & Medicaid Services provided guidelines on the Patient Protection and Affordable Care Act’s 60-day repayment requirements for self-identified overpayments will be interpreted and applied as follows: