The Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) requires the CMS to remove Social Security Numbers (SSN’s) from all Medicare cards by April 2019
https://www.cms.gov/Outreach-and-Education/Outreach/FFSProvPartProg/Provider-Partnership-Email-Archive-Items/2016-09-29-eNews.html?DLPage=1&DLEntries=10&DLSort=0&DLSortDir=descending#_Toc462812247