FAQ / Social Security and Medicare faxing
Social Security and Medicare faxing
How to find a local SSA fax number and what to put on the cover sheet.
Is there one national Social Security fax number?
No. Many forms (including Medicare Part B enrollment on CMS-40B) are faxed to your local Social Security office. Use the SSA Field Office Locator to find that office’s fax number.
What should I put on the cover?
Your name, Social Security number or Medicare number as the form requires, the form name, and a callback phone number. Follow any checklist on the form instructions.
Why don’t you list a single SSA number in the directory?
Because a wrong national number wastes a send and can miss a deadline. We only publish numbers we can point to an official source for—and for SSA that source is usually your local office.