Billers and coders regularly confront a challenge when 2 procedures are performed on the same day for a patient. Can both procedures be submitted for reimbursement? The answer is not always obvious, due to restrictions in both the Current Procedural Terminology (CPT) codebook and from the Centers for Medicare and Medicaid Services (CMS). The CPT codebook restricts billing for procedures that include the term “separate procedure,” while CMS limits procedure billing with its National Correct Coding Initiative (NCCI) edits, colloquially known as “bundles.” However, there are some exceptions to these rules, which involve the use of modifier -59 or one of the X modifiers (Table 1).
The potential for additional reimbursement creates an incentive to bill multiple codes, but this is often done incorrectly; according to government audits, about 40% of such claims resulted in improper payments.1 Billers and coders must understand when modifiers can be used for separate or unbundled procedures.
Q. What is a separate procedure?
A. According to the CPT codebook, some procedures or services are considered an “integral component of a total service or procedure.”2 They are identified with the term “separate procedure,” and should not be reported in addition to the total procedure or service code. For example, 66030 is defined as “Injection anterior chamber of eye (separate procedure); medication.” During cataract surgery (66982 or 66984), it is common to inject medication into the eye; however, 66030 and 66984 cannot be billed together on the claim for reimbursement, because the injection of medication is an integral component of the cataract surgery. The “separate procedure” term in the description alerts the biller to consider this point.3
However, CPT further explains that when a “separate procedure” is carried out independently or is distinct from other services, the code may be reported by appending modifier -59 to indicate that the procedure is not a component of another procedure. “This may represent a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injury),” CPT says.4,5
For example, cataract surgery is performed on a diabetic patient, and during the procedure an intravitreal injection of an anti-VEGF agent for diabetic retinopathy is performed. CPT code 67028 is defined as “Intravitreal injection of a pharmacologic agent (separate procedure).” Can 67028 and 66984 be billed together on the claim for reimbursement? Yes, because the anti-VEGF injection is made through a different incision (pars plana) and in a different site (the posterior segment).6 It is noteworthy that billing software identifies 67028 and 66984 as bundled, even though these codes can be unbundled under certain circumstances.7
Q. How do I select the modifier?
A. Claims that involve separate procedures or NCCI bundled procedures require either modifier -59 or one of the X modifiers (XE, XS, XP, XU). CPT says, “Modifier -59 is used to identify procedures or services, other than E/M services, that are not normally reported together but are appropriate under the circumstances.”8 However, CPT also notes that when a more specific modifier best explains the circumstances for unbundling, it should be used instead. X modifiers are more specific than modifier -59. However, X modifiers are part of HCPCS, not CPT, so some clearinghouses and some payors may not recognize or accept them.
The X modifiers are used in situations where services are distinct and modifier -59 does not fully describe the distinction. Some payors prefer them instead of modifier -59.
Q. What are some examples of X modifier usage?
A. The XE modifier is used for a service that is distinct because it occurred during a separate encounter (think E for encounter). This involves a separate visit or session on the same day by the same provider or providers within the same group. For example, gonioscopy (92020) is defined in CPT as a “separate procedure.” If gonioscopy is performed in the morning in the clinic, followed by laser trabeculoplasty in the afternoon at the ambulatory surgery center by the same physician, then gonioscopy
is billed as 92020-XE. (It is noteworthy that billing software identifies 92020 and 65855 as bundled, but these codes may be unbundled under certain circumstances, as in this case and the 3 that follow.)
The XS modifier is used for a service that is distinct because it was performed on a separate organ or structure (think S for structure). Medicare defines a different anatomic site as one that “includes different organs or different lesions in the same organ. However, it does not include treatment of contiguous structures of the same organ.... Treatment of posterior segment structures in the eye constitute a single anatomic site.”8 Different portions of the same retina or different areas of the same eyelid do not constitute a different structure. For example, NCCI edits bundle prophylaxis of retinal tear (67145) with retinal detachment repair (67108). When the prophylaxis and repair are performed in 2 different eyes by the same surgeon on the same day, then prophylaxis is billed as 67145-XS.
The XP modifier is used for a service that is distinct because it was performed by a different practitioner (think P for practitioner). This modifier applies when different providers in the same group are involved in the care of a single patient. For example, an optometrist performs extended ophthalmoscopy (92201) and identifies a retinal tear in the left eye. Later the same day, an ophthalmologist in the same group practice lasers the retinal tear (67145-LT). The optometrist’s claim for extended ophthalmoscopy would read 92201-XP.
The XU modifier is used for a service that is distinct because it does not overlap usual components of the main service (think U for unusual). Use modifier XU for a diagnostic procedure that is performed before a therapeutic procedure when the diagnostic procedure is the basis for performing the therapeutic procedure.8 For example, an infant with buphthalmos is examined under general anesthesia (92018) and, based on that assessment, the doctor decides to perform goniotomy (65820) later the same day for uncontrolled congenital glaucoma. The claim for the exam under anesthesia would read 92018-XU.
Now, consider a different example. A doctor performs perimetry, optical coherence tomography (OCT) of the optic nerve, fundus photography (FP), and gonioscopy on a new patient with uncontrolled, moderate glaucoma in both eyes. NCCI bundles OCT and FP. This is not a separate encounter, structure, practitioner, or an unusual, nonoverlapping procedure. So, using modifier -59 or an X modifier would not be appropriate. OCT and FP are only different images of the optic disc in glaucoma, so only 1 imaging service is reimbursed; the second one is incidental and bundled.
Conclusion
The concepts that support billing for 2 procedures on the same day that are otherwise bundled are subtle. The biller, coder, or physician should appreciate that they do not apply in every case, but only in a minority of cases. Abuse of modifier -59 and X modifiers have been identified by OIG and payors. Accurate billing ensures that healthcare providers are reimbursed fairly for the services they provide while maintaining compliance with coding standards. RP
References
1. Department of Health and Human Services Office of the Inspector General. Use of modifier -59 to bypass Medicare’s National Correct Coding Initiative edits. November 2005. Accessed August 28, 2024. https://oig.hhs.gov/oei/reports/oei-03-02-00771.pdf
2. 2024 CPT Professional Edition, Surgery Guidelines, Separate Procedure
3. Fletcher TA. Coding “separate procedures”: what coders need to know. ICD10 Monitor. February 26, 2019. Accessed August 28, 2024. https://icd10monitor.medlearn.com/coding-separate-procedures-what-coders-need-to-know
4. AAPC Knowledge Center. A quick guide to “separate procedures.” August 2, 2013. Accessed August 28, 2024. https://www.aapc.com/blog/25335-a-quick-guide-to-separate-procedures/
5. Verhovshek J. Separate procedure coding. AAPC Knowledge Center. January 19, 2015. Accessed August 28, 2024. https://www.aapc.com/blog/29062-separate-procedure-coding/
6. Medicare Learning Network. Proper use of modifiers -59, XE, XP, XS, and XU. February 2024. Accessed August 28, 2024. https://www.cms.gov/files/document/mln1783722-proper-use-modifiers-59-xe-xp-xs-and-xu.pdf
7. Centers for Medicare and Medicaid Services. Medicare National Correct Coding Initiative (NCCI) edits. Updated September 10, 2024. Accessed September 30, 2024. https://www.cms.gov/medicare/coding-billing/ncci-medicare
