Field 9c of the CMS 1500 form is reserved for NUCC use. Leave Blank

MEDICARE INSTRUCTIONS - Leave blank if item 9d is completed. Otherwise, enter the claims processing address of the Medigap insurer. Use an abbreviated street address, two-letter postal code, and ZIP code copied from the Medigap insured's Medigap identification card. For example:

1257 Anywhere Street
Baltimore, MD 21204

is shown as "1257 Anywhere St. MD 21204."