CMS has added effective dates and deletion dates, where appropriate, for each of the Medicare Add-on Code Edits to aid in determining the active period of an add-on code edit for Medicare Services.  The earliest effective date April 1, 2013 coincides with the implementation of the Change Request 7501.

An add-on code is a HCPCS/CPT code that describes a service that, with one exception (see CR7501 for details), is always performed in conjunction with another primary service.  An add-on code with one exception is eligible for payment only if it is reported with an appropriate primary procedure performed by the same practitioner. An add-on code with one exception is never eligible for payment if it is the only procedure reported by a practitioner.

Add-on codes may be identified in three ways:
1. The code is listed in this CR or subsequent ones as a Type I, Type II, or Type III add-on code.
2. On the Medicare Physician Fee Schedule Database an add-on code generally has a global surgery period of “ZZZ”.
3. In the CPT Manual an add-on code is designated by the symbol “+”. The code descriptor of an add-on code generally includes phrases such as “each additional” or “(List separately in addition to primary procedure).”

CMS has divided the add-on codes into three groups to distinguish the payment policy for each group.

1. Type I – A Type I add-on code has a limited number of identifiable primary procedure codes. The CR lists the Type I add-on codes with their acceptable primary procedure codes.  A Type I add-on code, with one exception, is eligible for payment if one of the listed primary procedure codes is also eligible for payment to the same practitioner for the same patient on the same date of service.  Claims processing contractors must adopt edits to assure that Type I add-on codes are never paid unless a listed primary procedure code is also paid.

2. Type II – A Type II add-on code does not have a specific list of primary procedure codes. The CR lists the Type II add-on codes without any primary procedure codes. Claims processing contractors are encouraged to develop their own lists of primary procedure codes for this type of add-on codes.  Like the Type I add-on codes, a Type II add-on code is eligible for payment if an acceptable primary procedure code as determined by the claims processing contractor is also eligible for payment to the same practitioner for the same patient on the same date of service.

3. Type III – A Type III add-on code has some, but not all, specific primary procedure codes identified in the CPT Manual. The CR lists the Type III add-on codes with the primary procedure codes that are specifically identifiable.  However, claims processing contractors are advised that these lists are not exclusive and there are other acceptable primary procedure codes for add-on codes in this Type. Claims processing contractors are encouraged to develop their own lists of additional primary procedure codes for this group of add-on codes.  Like the Type I add-on codes, a Type III add-on code is eligible for payment if an acceptable primary procedure code as determined by the claims processing contractor is also eligible for payment to the same practitioner for the same patient on the same date of service.

CMS will update the list of add-on codes with their primary procedure codes on an annual basis on or by January 1 every year based on changes to the CPT Manual or HCPCS Level II Manual.  Quarterly updates will be posted as necessary on April 1, July 1, and October 1 each year.  If no changes occur in the add-on code edits for one quarter, no quarterly update will be posted.