The online system that health care providers use to enroll in the Medicare program will be unavailable from March 29 through April 5 due to scheduled maintenance, the Centers for Medicare & Medicaid Services announced today. Providers wishing to enroll or make changes to their enrollment information while the online Provider Enrollment, Chain and Ownership System is down can complete and mail a paper Medicare provider enrollment application to their Medicare administrative contractor, carrier or fiscal intermediary. For additional information or assistance, providers should contact the Medicare fee-for-service contractor serving their state.