Understanding Add-On Codes for 2023 and Beyond

Knowing the basics of radiology and interventional radiology are imperative for successful coding and building a robust knowledge foundation. Among the key coding knowledge topics are gaining an understanding of the components of add-on codes, when applicable, and how to use them correctly. According to CMS, an add-on code is a HCPCS/CPT code that details a service that, with one exception (see CR7501 for details), is always performed in conjunction with another primary service. Furthermore, 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. Understand that CMS explicitly explains that an add-on code (with one exception) is never eligible for payment if it is the only procedure reported by a practitioner. It is important to meticulously review CR 7501 for the scenario in which billing for the add-on code without the primary code is defined as correct by CMS.

Avenues to Identify Add-On Codes

So, how do we go about identifying add-on codes? According to CMS, three techniques exist to help master identification:

• First, note whether the code is listed in the CMS CR (or subsequent ones) as a Type I, Type II, or Type III add-on code.
• Second, examine the Medicare Physician Fee Schedule Database to determine whether the code has a global surgery period of “ZZZ.” This is generally an indicator that the code is an add-on code.
• Finally, in the CPT Manual an add-on code is designated by the symbol “+”. Moreover, the code descriptor of an add-on code generally includes key indicator phrases such as “each additional” or “(List separately in addition to primary procedure).”

There are three distinct types of add-on codes that we will explore below.

Type I Add-On Codes

Type I add-on codes contain a limited number of identifiable primary procedure codes. Understand in the CR, CMS lists the Type I add-on codes with their acceptable primary procedure codes. Note that 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.

Type II Add-On Codes

 Type II add-on codes differ from Type I and Type III because they do not have a specific list of primary procedure codes. The CR details the Type II add-on codes without any primary procedure codes.

Understand that CMS wants claims processing contractors to create their own lists of primary procedure codes for these types of add-on codes. Similar to 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.

Type III Add-On Codes

Finally, Type III add-on codes contain some, but not all, specific primary procedure codes identified in the CPT^® Manual. Note that the CR details the Type III add-on codes with the primary procedure codes that are specifically identifiable.

Here things get a little trickier in terms of CMS recommendations and guidelines. 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 code type. CMS wants claims processing contractors to create 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.

These are not all the necessary coding tips and rationale essential for basic interventional radiology knowledge. As service volumes rebound, now more than ever, it is imperative to make sure your CPT® coding is correct and compliant. Master more interventional radiology topics and break down the complexity with expert-infused insight. Our Basics of Interventional Radiology Coding webcast, live on January 18, 2023, is an essential training tool for both audio and visual learners.