CMS is modifying the data collection period and data reporting period, as defined at 42 CFR § 414.626(a), for ground ambulance organizations (as defined at 42 CFR § 414.605) that were selected by CMS under 42 CFR § 414.626(c) to collect data beginning between January 1, 2020 and December 31, 2020 (year 1) for purposes of complying with the data reporting requirements described at 42 CFR § 414.626. Under this modification, these ground ambulance organizations can select a new continuous 12-month data collection period that begins between January 1, 2021 and December 31, 2021, collect data necessary to complete the Medicare Ground Ambulance Data Collection Instrument during their selected data collection period, and submit a completed Medicare Ground Ambulance Data Collection Instrument during the data reporting period that corresponds to their selected data collection period. CMS is modifying this data collection and reporting period to increase flexibilities for ground ambulance organizations that would otherwise be required to collect data in 2020- 2021 so that they can focus on their operations and patient care. As a result of this modification, ground ambulance organizations selected for year 1 data collection and reporting will collect and report data during the same period of time that will apply to ground ambulance organizations selected by CMS under 42 CFR § 414.626(c) to collect data beginning between January 1, 2021 and December 31, 2021 (year 2) for purposes of complying with the data reporting requirements described at 42 CFR § 414.626.