Health insurance is confusing! Seniors over the age of 65 aren’t the only ones who get overwhelmed by Medicare enrollment forms. Trying to get your head around the terminology is enough to give anyone a headache. However, as difficult as it may seem, understanding the different CMS-855 applications is key for healthcare providers who treat seniors.

1. Medicare Provider Enrollment: Which
CMS-855 Form Do YOU Need?
Health insurance is confusing! Seniors over the age of 65 aren’t the only ones who get
overwhelmed by Medicare enrollment forms. Trying to get your head around the terminology is
enough to give anyone a headache. However, as difficult as it may seem, understanding the
different CMS-855 applications is key for healthcare providers who treat seniors.
If you are a provider who wants to enroll in Medicare, you will need to fill out a CMS-855 form.
The current version is available for download at the Centers for Medicare & Medicaid Services
(CMS) website. PDF forms must be printed and filled in manually, while electronic forms may be
completed online.
There are several types of CMS-855 forms to choose from depending on WHO you are and
WHAT you plan to do once enrolled.
1. CMS-855B is used by organizations or groups that are enrolling in Medicare for the first
time in a given state or that are reporting a change to previously reported enrollment
information.
2. CMS-855I is used by individual physicians and practitioners who are enrolling in
Medicare for the first time in a given state or who are reporting changes to previously
reported enrollment information.
 Individuals who are the sole owner of a professional corporation, professional
association, or limited liability company and who bill through that entity may
complete just the CMS 855I. They are not required to complete the CMS 855B.
 Physician assistants also complete a CMS-855I.
3. CMS-855O is used by individual physicians or practitioners who are enrolling for the sole
purpose of ordering and referring items and/or services for Medicare beneficiaries and
who will not be submitting claims to the Medicare program for their own services.
 For example, the Department of Veterans Affairs and Public Health Service
providers would use a CMS-855O.
4. CMS-855R is used by individual physicians or practitioners who are reassigning Medicare
benefits to an enrolled group, organization, or individual or who are making a change to
a previously established reassignment.