Differentiate Separate Procedures with Modifiers 59 and X[ESPU]

Modifiers ProceduresWhen you have distinct, separate procedures, know which modifiers procedures will get the claim paid in full.

Modifier 59 Distinct procedural service acts as a “universal unbundling” modifier for procedures that are normally included as part of another procedure, or “bundled.” The modifier tells the payer that there are special circumstances that warrant separate reporting (and payment) of the unbundled code.

  • Special circumstances that generally warrant modifier 59 include:
  • The procedures were performed at separate encounters on the same day.
  • The procedures were performed during the same encounter on separate anatomic organ systems or body sites, incisions, excisions, lesions, or injuries.
  • The procedures were timed and performed sequentially.
  • The diagnostic procedure preceded and was the basis for a therapeutic procedure.
  • An unplanned diagnostic procedure occurred subsequent to the therapeutic procedure.
Be Accurate, Avoid Denials

Because claims are processed without the physician’s documentation, payers rely on the information sent to them to be accurate and assume there is documentation backing it up. Unfortunately, modifier 59 gets misused a lot. As a result, some payers now automatically deny CPT® codes appended with modifier 59. This forces the provider to appeal the denial and send in the documentation to show that modifier 59 was applied correctly. This denial and appeal process is costly for both the provider and the payer — it delays payment and forces the provider’s staff to write appeals and the payer’s staff to read documentation and process appeals.

New Modifiers Replace Modifier 59

The Centers for Medicare & Medicaid Services (CMS) created four new modifiers procedures, referred to as X[ESPU], to better differentiate between the reasons for unbundling codes:

XE Separate encounter

XS Separate structure

XP Separate practitioner

XU Unusual non-overlapping service

These modifiers apply to Medicare Part B. Some commercial insurance companies have indicated in their online reimbursement manuals they will process the X[ESPU] modifiers, as well, such as Horizon Blue Cross Blue Shield of New Jersey.

CMS does not require providers to use modifiers X[ESPU] in place of modifier 59, and they continue to accept modifier 59, for now. However, if your practice ignores the modifiers which carry more specific information and uses modifier 59 instead, do not be surprised if your Part B carrier audits your modifier 59 usage to make sure it’s not being over-utilized to unbundle CPT® codes. Be sure to review the documentation and ask yourself if the unbundling is justified enough to apply the appropriate X[ESPU] modifier.

Let’s look at some examples of when each of the “X” modifiers procedures are used.

Modifier XE

This modifier tells the payer that the service is distinct because it occurred during a separate encounter on the same date of service as the bundled procedure.


The patient sees the otolaryngologist in the morning, at which time the doctor performs an evaluation and management (E/M). During the visit, the patient complains of nasal congestion and headaches and the doctor performs a diagnostic nasal endoscopy. The visit is coded:

99213-25 – Office or other outpatient visit for the evaluation and management of an established patient, which requires at least 2 of these 3 key components: An expanded problem focused history; An expanded problem focused examination; Medical decision making of low complexity. -Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service.

31231 – Nasal endoscopy, diagnostic, unilateral or bilateral (separate procedure)

That evening, the patient experiences a severe nosebleed and goes to the emergency room (ER). The ER physician is unable to stop the bleeding and calls the otolaryngologist in. The otolaryngologist comes to the ER and performs an extensive control of the nasal hemorrhage with packing. This encounter in the ER for the otolaryngologist is coded:

30903 – Control nasal hemorrhage, anterior, complex (extensive cautery and/or packing) any method

CPT® 30903 is a National Correct Coding Initiative (NCCI) Column 2 code for 31231, meaning the two codes are bundled and not separately payable. Appending modifier XE to 30903 tells the payer that the procedure performed in the ER was a separate encounter from the diagnostic nasal endoscopy performed that same day in the office.

Modifier XS

This modifier tells the payer the procedure is distinct because it was performed on a separate organ or structure than the bundled procedure.


The patient arrives at an orthopedist for a knee injection with ultrasound guidance on the left knee and an aspiration of the right knee without ultrasound guidance. Coding is:

20611-LT – Arthrocentesis, aspiration and/or injection, major joint or bursa (eg, shoulder, hip, knee, subacromial bursa); with ultrasound guidance, with permanent recording and reporting -Left side

20610-XS-RT – Arthrocentesis, aspiration and/or injection, major joint or bursa (eg, shoulder, hip, knee, subacromial bursa); without ultrasound guidance -Right side

20610 is a Column 2 code for 20611. Modifiers procedures for  LT and RT seem to be enough, telling the payer that the two procedures were performed on two different sides, but not all payers allow modifiers LT and RT to break a bundle. Modifier XS or modifier 59 is needed to break the bundle.

Modifier XP

This modifier tells the payer that the service is distinct from the bundled service because it was performed by a different practitioner.


A colorectal surgeon performs 44147 Colectomy, partial; abdominal and transanal approach while another surgeon in the group performs +38747 Abdominal lymphadenectomy, regional, including celiac, gastric, portal, peripancreatic, with or without para-aortic and vena caval nodes (List separately in addition to code for primary procedure). CPT® +38747 is a Column 2 code of 44147, but since a different physician performed this procedure, modifier XP is used to break the bundle. Coding is: 44147, 38747-XP.

Modifier XU

This modifiers procedures tells the payer that the service is distinct because it does not overlap usual components of the main service.


The otolaryngologist performs a rigid diagnostic nasal endoscopy for nasal complaints, and then pulls out the rigid endoscope and performs a flexible laryngoscopy to evaluate the patient’s complaints of coughing, throat clearing, and difficulty swallowing.

A nasal endoscopy and flexible laryngoscopy are not usually both coded and charged during the same encounter because the same scope can be used for both diagnostic procedures. This encounter is coded:

31231-XU-Nasal endoscopy, diagnostic, unilateral or bilateral (separate procedure)

31575-Laryngoscopy, flexible; diagnostic

CPT® 31231 is coded whether a rigid endoscope or a flexible endoscope is used, and it’s a Column 2 code of 31575. Interestingly, 31231 has more relative value units (RVUs) than 31575, and should be listed first.

Apply New CMS Claims Processing Logic

CMS issued on Feb. 15, 2019, Transmittal 2259 to relay a modification to the claims processing logic for modifiers procedures for 59, XE, XS, XP, and XU. These modifiers were being processed only when applied to the Column 2 code in a bundled pair, per NCCI, with a modifier indicator “1.” This meant if the separate procedure modifier was appended on the Column 1 code, the modifier would not override the edit and the system would reject the code. Our modifier XU example would not have been paid because the XU was used on the Column 1 code, as it carries less RVUs than the Column 2 code.

CMS carriers will now process the separate procedure modifier when it’s used on either the Column 1 procedure or the Column 2 procedure, effective July 1, 2019. The NCCI bundling edit will be bypassed when modifier 59, XE, XS, XP, or XU is used on either the Column 1 code or Column 2 code. This is good news.

Why does this make a difference? There were separate procedure modifier edit bypasses being ignored when appended to the Column 1 code. This required a corrected claim to be resubmitted for reprocessing and caused additional cost to both the provider and the carrier.

Why are separate procedure modifiers being put on Column 1 codes to get an edit bypassed? This usually happens when the Column 1 code carries less RVUs than the Column 2 code, as described in the above XU example. As a result, the Column 2 code appears before the Column 1 code on the claim because CPT® codes are placed in RVU order to minimize the effects of multiple procedure discounts taken by the payer. Placing a separate procedure modifier on the first of the two codes bundled on the claims appears awkward and, as a result, the biller tends to put modifier 59, XE, XS, XP, or XU on the bundled CPT® appearing lower in the claim. The new instruction allows a more billing-friendly approach for applying the separate procedure modifier.

With this guidance, the above modifier XU example is billed on the claim as follows (consistent with the RVUs): 31231, 31575-XU.

For More Information: https://www.aapc.com/blog/47620-differentiate-separate-procedures-with-modifiers-59-and-xespu/

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