Consider this scenario: A patient comes in for a glaucoma workup after being identified as a suspect during last week’s annual exam. During this follow-up office visit (9921X) you want to do: optical coherence tomography (OCT) optic nerve (92133), fundus photography (92250), pachymetry (76514) and threshold visual fields (92083).

The Temptation

You know fundus photography and OCT of the optic nerve are not allowed on the same date of service. However, you have heard certain modifiers, such as -59, can “override” these rules on the claim form so you can get paid for both services. So what should you do? Let’s take a look.

Where to Start

The rules that govern situations such as this one are the National Correct Coding Initiative (NCCI) edits, which are found in CMS’s NCCI Policy Manual For Medicare Services, published yearly and updated quarterly. These edits control the pairing of procedures on the same date of service.1 

Understanding these code pairing rules and their context is crucial, especially when applying a modifier that will override a claim pair denial. One of the most abused modifiers is -59. 

CMS Definition

To properly use a modifier, you must know both the definition and its proper application. Modifier -59 is used to identify procedures/services, other than E/M services, that are not normally reported together, but are appropriate under the circumstances. Documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion or separate injury (or area of injury if extensive) not ordinarily encountered or performed on the same day by the same individual. Modifier -59 can be used appropriately in these situations (remember, the eye is considered a single anatomic structure and site):2,3 

“Modifier -59 is used appropriately for different anatomic sites during the same encounter only when procedures which are not ordinarily performed or encountered on the same day are performed on different organs, or different anatomic regions, or in limited situations on different, non-contiguous lesions in different anatomic regions of the same organ.”3

“Another common use of modifier -59 is for surgical procedures, non-surgical therapeutic procedures or diagnostic procedures that are performed during different patient encounters on the same day and that cannot be described by one of the more specific NCCI-associated modifiers—i.e., 24, 25, 27, 57, 58, 78, 79 or 91. As noted in the CPT definition, modifier -59 should only be used if no other modifier more appropriately describes the relationship of the two procedure codes.”3


Modifier -59 should not be appended to an E/M service. To report a separate E/M service with a non-E/M service performed on the same date, use modifier -25.4 

You should never use modifier -59 to bypass a PTP edit unless you meet and document the proper criteria required by any NCCI-associated modifier. The use of modifier -59 does not require a different diagnosis for each HCPCS/CPT coded procedure; conversely, different diagnoses are not adequate criteria for use of modifier -59. The HCPCS/CPT codes remain bundled unless the procedures are performed at different anatomic sites or separate patient encounters.4


Modifier -59 is used inappropriately if the basis for its use is simply that the narrative description of the two codes is different.

One of the common misuses of modifier -59 is related to the portion of the definition allowing its use to describe a “different procedure or surgery.” The code descriptors of the two codes of a code pair edit usually represent different procedures, even though they may be overlapping. The edit indicates that the two procedures should not be reported together if performed at the same anatomic site and same patient encounter, as those procedures would not be considered “separate and distinct.” 

However, if the two procedures are performed at separate anatomic sites or at separate patient encounters on the same date of service, modifier -59 may be appended to indicate that they are different procedures on that date of service.

-59 in Your Office

In ophthalmic practice, the most common combination with which modifier -59 is improperly used is CPT codes 92250 and 92133/92134. The NCCI manual specifically states: “Fundus photography (92250) and scanning ophthalmic computerized diagnostic imaging (e.g., 92133, 92134) are generally mutually exclusive of one another in that a provider would use one technique or the other to evaluate fundal disease. 

As with most rules, a few exceptions exist, and there are a limited number of clinical conditions where both techniques are medically reasonable and necessary on the ipsilateral eye. In these situations, both CPT codes may be reported appending modifier -59 to CPT code 92250.”5

Those limited number of clinical conditions must meet the definition of medical necessity, i.e., patient harm could be a result if the two tests aren’t performed on the same date of service. This does not mean there is a wholesale acceptance of this code combination with modifier -59 just because the doctor thinks it’s appropriate or because it is convenient for either the doctor or the patient.

For our case example, using modifier -59 on the fundus photography code might get you paid, but it is not appropriate. You must first establish proper medical necessity for each procedure that you need to perform. Remember, modifier -59 is a last resort and should be used sparingly in clinical practice.

Send questions and comments to

1. Centers for Medicare and Medicaid Services (CMS). National Correct Coding Initiative Edits. Accessed February 22, 2018.
2. CMS. Modifier 59 Article. Accessed February 22, 2018. 
3. CMS. Proper Use of Modifier 59. Accessed February 22, 2018.
4. CMS. NCCI Policy Manual For Medicare Services – Effective January 1, 2018:I-20, I-25, III-18, IV-23, V-29, VI-19, VII-20, VIII-26, IX-25, XI-12. XI-52, XII-21, XIII-10. Accessed February 22, 2018.
5.  CMS. NCCI Policy Manual For Medicare Services – Effective January 1, 2018:XI-12. Accessed February 22, 2018.