Modifier 59: Appropriate Use

Modifier 59: Distinct Procedural
Service
Modifier 59 is an important NCCI (Medicare National Correct Coding Initiative)-associated modifier that is often used incorrectly. The CPT Manual defines modifier 59 as follows:
Distinct Procedural Service: Under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-E/M services performed on the same day. 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 in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. However, when another already established modifier is appropriate, it should be used rather than modifier 59. Only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used.
Modifier 59 should not be appended to an E/M service. To report a separate and distinct E/M service with a non-E/M service performed on the same date, if appropriate use modifier 25. Modifier 59 and other NCCI-associated modifiers should NOT be used to bypass a PTP edit unless the proper criteria for use of the modifier are met.
Appropriate Use of Modifier 59
Different Anatomic Sites During the Same Encounter
One of the common uses of modifier 59 is for surgical procedures, non-surgical therapeutic procedures, or diagnostic procedures that are performed at different anatomic sites, are not ordinarily performed or encountered on the same day, and that cannot be described by one of the more specific anatomic NCCI-associated modifiers – i.e., RT, LT, E1-E4, FA, F1-F9, TA, T1-T9, LC, LD, RC, LM, or RI. From an NCCI perspective, the definition of different anatomic sites includes different organs or, in certain instances, different lesions in the same organ.
However, NCCI edits are typically created to prevent the inappropriate billing of lesions and sites that should not be considered to be separate and distinct. Therefore modifier 59 should only be used to identify clearly independent services that represent significant departures from the usual situations described by the NCCI edit. The treatment of contiguous structures in the same organ or anatomic region does not constitute treatment of different anatomic sites. For example:
- Treatment of the nail, nail bed, and adjacent soft tissue on the same toe or finger constitutes treatment of a single anatomic site.
- Treatment of posterior segment structures in the eye constitutes treatment of a single anatomic site.
- Arthroscopic treatment of structures in adjoining areas of the same shoulder constitutes treatment of a single anatomic site.
Different Encounters on the Same Day
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.
Other Specific Appropriate Uses of Modifier 59
There are three other limited situations in which two services may be reported as separate and distinct because they are separated in time and describe non-overlapping services even though they may occur during the same encounter.
- Modifier 59 is used appropriately for two services described by timed codes provided during the same encounter only when they are performed sequentially. There is an appropriate use for modifier 59 that is applicable only to codes for which the unit of service is a measure of time (e.g., per 15 minutes, per hour). If two timed services are provided in blocks of time that are separate and distinct (i.e., the same time block is not used to determine the unit of service for both codes), modifier 59 may be used to identify the services.
- Modifier 59 is used appropriately for a diagnostic procedure which precedes a therapeutic procedure only when the diagnostic procedure is the basis for performing the therapeutic procedure. When a diagnostic procedure precedes a surgical procedure or non-surgical therapeutic procedure and is the basis on which the decision to perform the surgical procedure is made, that diagnostic test may be considered to be a separate and distinct procedure as long as (a) it occurs before the therapeutic procedure and is not interspersed with services that are required for the therapeutic intervention; (b) it clearly provides the information needed to decide whether to proceed with the therapeutic procedure; and (c) it does not constitute a service that would have otherwise been required during the therapeutic intervention. (See example 10) If the diagnostic procedure is an inherent component of the surgical procedure, it should not be reported separately.
- Modifier 59 is used appropriately for a diagnostic procedure which occurs subsequent to a completed therapeutic procedure only when the diagnostic procedure is not a common, expected, or necessary follow-up to the therapeutic procedure. When a diagnostic procedure follows the surgical procedure or non-surgical therapeutic procedure, that diagnostic procedure may be considered to be a separate and distinct procedure as long as
- It occurs after the completion of the therapeutic procedure and is not interspersed with or otherwise commingled with services that are only required for the therapeutic intervention, and
- It does not constitute a service that would have otherwise been required during the therapeutic intervention. If the post-procedure diagnostic procedure is an inherent component or otherwise included (or not separately payable) post-procedure service of the surgical procedure or non-surgical therapeutic procedure, it should not be reported separately.
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 the use of modifier 59. The HCPCS/CPT codes remain bundled unless the procedures are performed at different anatomic sites or separate patient encounters or meet one of the other three scenarios described above.
Inappropriate Use of Modifier 59
One of the common misuses of modifier 59 is related to the portion of the definition of modifier 59 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, in general, should not be reported together if performed at the same anatomic site and same patient encounter as those procedures would not be considered to be “separate and distinct.”
The provider should not use modifier 59 for such an edit based on the two codes being “different procedures.” 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. Additionally, there may be limited circumstances sometimes identified in the National Correct Coding Initiative Policy Manual for Medicare Services when the two codes of an edit pair may be reported together with modifier 59 when performed at the same patient encounter or at the same anatomic site.
Modifiers XE, XS, XP, and XU
Modifiers XE, XS, XP, XU were developed to provide greater reporting specificity in situations where modifier 59 was previously reported and may be utilized in lieu of modifier 59 whenever possible. (Modifier 59 should only be utilized if no other more specific modifier is appropriate.) Although NCCI will eventually require the use of these modifiers rather than modifier 59 with certain edits. The modifiers are defined as follows:
- XE: “Separate encounter, A service that is distinct because it occurred during a separate encounter” This modifier should only be used to describe separate encounters on the same date of service.
- 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”
The biller should never be the one to add the 59 modifier to a claim, even if he knows that billing the services without the modifier will result in bundling or a denial. The 59 modifier should only be added by the provider or by a coder who has access to the patient’s chart. Misusing 59, or any other modifier can cause a payer to deny your claim altogether. Avoid claim issues by making sure to always use it properly.
Modifiers © Copyright 2021 American Medical Association
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