Modifier 59 Is Over-Used and Abused, MAC Says
- By Barbara Cobuzzi
- In Billing
- March 3, 2020
- 6 Comments

Failure to adopt the X[ESPU] modifiers may be putting your practice at risk for Medicare fraud.
Modifier 59 Distinct procedural service continues to be the most-used modifier among Medicare Part B providers, according to Novitas, and it is sending up red flags for possible Medicare fraud and abuse.
Representatives from the Medicare Administrative Contractor (MAC) for jurisdiction L relayed this to my Monmouth, New Jersey, local chapter meeting in on Jan. 2. I immediately asked the question: Does their usage data include the X[ESPU] modifiers that are supposed to replace modifier 59? The answer was “No, the usage is based only on the 59 modifier.” As a result, modifier 59 remains highest on Novitas’ audit radar.
Practices that continue to use modifier 59 are at high risk with payers that recognize the X[ESPU] modifiers.
Modifier 59 vs. X[ESPU] Modifiers
The X[ESPU] modifiers were implemented to replace modifier 59 because carriers were not comfortable with the high volume of modifier 59 usage, which they believe much to be non-compliant. MACs want providers to use the X[ESPU] modifiers because they require the medical coder to indicate why a procedure typically bundled into another procedure should be paid separately.
These new modifiers were implemented five years ago, in 2015. However, the Centers for Medicare & Medicaid Services (CMS) still allows providers to use modifier 59 if they did not want to use the new X[ESPU] modifiers. The data quoted by the Novitas representatives tells us that providers continue to use modifier 59 over the X[ESPU] modifiers.
For whatever reason CMS continues to allow the use of modifier 59, the result is putting practices at risk for unbundling procedures incorrectly. It is very important for practices that want to avoid audit risk and receive payment to start using the X[ESPU] modifiers to unbundle services, when appropriate.
Definitions for the X[ESPU] Modifiers
To remind what each of the four modifiers mean, here are their definitions:
- XE – Separate encounter, a service that is distinct because it occurred during a separate encounter
- XS – Separate structure, a service that is distinct because it was performed on a separate organ/structure
- XP – Separate practitioner, a service that is distinct because it was performed by a different practitioner
- XU – Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
You need to tell your payer why you are unbundling two services. You can do this by using the X[ESPU] modifiers.
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Thanks for your inputs. Well explained
I tried to used the X modifiers when they first were implemented and Blue Cross, Regence and Medicaid were denying claims for them. They said they wanted modifier 59 to be used. Funny how that works.
I tried to used the X modifiers when they first were implemented and Blue Cross, Regence and Medicaid were denying claims for them. They said they wanted modifier 59 to be used. Funny how that works.
For me, this needs expanded clarification, and I would need to see examples. The only one I really understand is XS. Even then, I frequently code shoulder surgeries, and Medicare doesn’t even recognize separate structures in the shoulder; it considers the shoulder a single , anatomic structure. Why would you even use XE? If it were a separate encounter, wouldn’t you just create a separate encounter? For XP, if it were a separate practitioner, wouldn’t you just use 80, 62 or AS to designate their part? For XU, I would need examples of when this would be appropriate. Sometimes, 59 is used to distinguish something as a separately identifiable procedure when it is above and beyond a normal surgery situation, which requires extra work.
For us we try to bill 92507, with 97535 (59), 97530 (59) and Still get denied. The mods are used correctly. Anthem truly does not follow regardless.
XU modifier example:
A physician performs a biopsy of a skin lesion on the right side of the patient’s forehead (11102) and uses cryotherapy to destroy a lesion in the left side of the patient’s forehead (17000). XU Modifier would be appropriate to indicate the lesions, although on the same body part, are not overlapping or are not contiguous locations. 17000, 11102-XU
59 modifier is not to be used, insurance is requesting X modifiers instead as they are more descriptive.