Beginning in April, the Centers for Medicare & Medicaid Services (CMS) will be mailing all Medicare beneficiaries new Medicare cards that remove their social security numbers. The change is intended to prevent fraud and identity theft. CMS will be mailing the new cards in waves between April and June 2018, with more details on the timing here. CMS has created an informational page for providers explaining what they need to do to get ready.
Source: AHCA