If you have Medicare claims system “dark days” marked on your calendar for May 12-May 15, get out your eraser. Why? “The Medicare Part A CMS Data Center Migration scheduled for 5/12/2023 to 5/15/2023 has been postponed,” HHH Medicare Administrative Contractor National Government Services says in a message to providers. Instead, the changeover has shifted later, and “claim submission will not be available from Friday evening, 5/19/2023 through Monday, 5/22/2023,” NGS says in a separate message. Plus: “Please continue to use Option 5,” NGS says. “Starting 5/23/2023 use Option 2.”