September 2016

Coding Corner: Modifier 59

Matthew D. Hepler, MD
Coding Committee Chair


There has been a significant increase in the number, breadth, and depth of spine procedures performed in the United States in the last two decades and, concomitant with these trends, an increasingly complex coding system for documentation and billing. This complexity combined with enhanced payor scrutiny has resulted in more audit activity, more claim reviews and denials, and more administrative burden. One of the most common billing errors is the improper use of modifiers and in the 2014 CMS (Centers for Medicare and Medicaid Services) identified modifier 59 as the most widely used and abused modifier leading to reviews, appeals, and allegation of civil fraud. This article will review the development and importance of modifier 59, explain its intended purpose, outline guidelines for its proper use, and discuss most recent CMS updates and guidelines.

History of CPT and Modifiers

CPT (Current Procedural Terminology) was first developed by the AMA in 1966 as a comprehensive list of bundled physician procedures. In 1983 HCFA (The Health Care Financing Administration, now the CMS) merged updated versions of CPT with its own HCPCS (Healthcare Common Procedure Coding System) to encompass all Medicare billing. Since that time, CPT has been maintained by the AMA through an editorial panel that meets each year to revise or delete old codes or add new codes which are then listed in the annually published CPT manual.  CMS uses the CPT codes as a basis for physician payment in the current fee-for-service system. Modifiers were introduced in 1992 to provide more details of coding scenarios (multiple procedures, staged procedures, return to OR, etc). Modifier 59 was added in 1997 to indicate when a procedure is distinct and independent from other services performed on the same day.  It soon became the most commonly used modifier prompting an OIG (Officer Inspector General) audit in 2005 which concluded 40% of Modifier 59 use was inappropriate resulting in $59 million in improper payments. It's been called the “unbundling” modifier and CMS believes it is used incorrectly to  “unbundle” procedures and bypass NCCI (National Correct Coding Initiative) edits resulting in double billing.  Understanding NCCI edits are fundamental to appreciate the development and proper use of Modifier 59.

NCCI edits

NCCI refers to National Correct Coding Initiative Edits. In 1995, a Government Account Office report found hundreds of millions of dollars in Medicare expenditures were the result of waste, fraud, and abuse. In response, Congress software mandated development to detect “unbundling”: billing of multiple procedures when one procedure/code would be appropriate. NCCI edits were developed to curb this coding abuse and these edits apply only to services which are provided by the same provider, on the same patient, on the same day; they apply to all physicians who bill for Medicare although third-party payers may also use NCCI edits.

The CCI edits consists of a list of CPT code “pairs” which generally should not be reported together by a provider on the same day of service. These code pairs are reported as Column 1 and Column 2 codes and CMS considers the column 2 codes to be a subset or inclusive of column 1 codes; in general, reporting both codes is inappropriate and constitutes full billing for separate codes which likely contain overlapping work. For example, 63030 (lumbar laminotomy) should generally not be billed with column 1 code 63047 (lumbar laminectomy) based on the CPT definition of these procedures since laminotomy is a subset or part of a laminectomy (Table1). There are circumstances when submitting both these codes is appropriate and CCI edits identify this possibility with the indicator “1” (column 5 of Table 1). For example, if a laminectomy (63047) is performed at 1 level and laminotomy (63030) at another level, submitting both codes is appropriate and identified by appending the appropriate modifier (in this case modifier 59) to indicate this is a distinct, separate procedure performed at a different anatomic site and therefore should be reimbursed. An indicator of “0” in the edit stipulates a modifier cannot be used to override the CCI edit in any circumstances. For instance, the NCCI edit for 63047 (laminectomy) and 62319 (injection, including indwelling catheter) has the indicator “0” and these codes should never be billed together as anesthesia is always included in the surgical procedure. There are other modifiers which can be used to override CCI edits and some of the more common ones include 25 (separate EM service), 50 (bilateral procedures), 58 (staged procedures), 59 (separate/distinct procedures), 76 (repeat procedure), 78 (return to OR for related procedure), 79(return to OR for unrelated procedures). A modifier should not be used to override a CCI edit unless the two procedures represent different sites, different encounters/operative sessions, separate anatomic locations, or a distinct service recognized by coding conventions.

Modifier 59

Modifier 59 was developed to identify procedures or services which are distinct or separate and not usually reported together, but may be appropriate under specific circumstances. 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. If no other descriptive modifier is available and the use of modifier 59 best explains the circumstances, should modifier 59 be used? Note: 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, see modifier 25.”

It is important to recognize that modifier 59 was developed for the rare occasion when there is an exception to a CCI edit and CMS, therefore, believes it should only be used when there is a permissive CCI edit. For example, a surgeon injects the right knee and right shoulder of the same patient on the same day. This combination should be reimbursable as two procedures are performed at different sites. There is only one code (20610 which is used twice) and no code combination CCI edit and in this situation, CMS does not want modifier 59 used. Similarly, modifier 51 can’t be used (there are not multiple stand-alone codes) and modifier 50 cannot be used (it is not a bilateral procedure). As a result, CMS recommends using modifier 76. This, however, is not a CPT rule and some private payors may not only allow but actually prefer using modifier 59 in this situation; check each carrier regarding policy and interpretation of 59.

Another important point to remember is modifier 59 should only be used when another established modifier does not better describe the scenario. 59 should be the modifier of last resort. If bilateral (50), multiple (51), staged (58), repeat (76), or other procedure modifiers can describe the procedure they should be used, not modifier 59. A common example is a multilevel interbody procedure performed with interbody “cage“(intervertebral mechanical device) used in ALIF, XLIF, or T/PLIF procedures. In this situation, there is no add-on code as there is for both the fusion and decompression procedures and it is not a stand-alone procedure (in which case the multiple procedure 51 modifier could be used). Therefore, modifier 59 best explains this “distinct procedure” and would be appropriate. It should not be used for a second device at the same level (2 cages in one interspace) as that would not be a separate and distinct procedure.

One of the more common uses of modifier 59 is to identify a procedure performed at a different anatomic site especially if it represents a different lesion or injury. As the example above demonstrated, it would be appropriate to bill 63047 (lumbar laminectomy) with 63030-59 (lumbar discectomy) to indicate the procedures were performed at two different levels; these codes would otherwise not be allowed due to the CCI edit that considers laminotomy/discectomy a subset of laminectomy. Modifier 59 would not be appropriate if the second procedure is adjacent to and merely an extension of the initial laminectomy.  Similarly, if a patient underwent a thoracic posterior decompression, fusion and instrumentation (T11-T12) followed by a lumbar decompression, fusion, and instrumentation (L5/S1) at the same encounter through a separate incision it would be appropriate to use 59 to indicate a separate, distinct procedure was performed. The appropriate codes to use would include 22610, 63047-51, 22840 and 22612-59, 63047-51-59, 22840-59. Again, it would not be appropriate to use modifier 59 if the lumbar procedure was adjacent to and an extension of the T11-T12 procedure. Of course, these are uncommon scenarios and would rarely be encountered and reported. 

Another modifier 59 scenario which generates confusion is the use of a laminectomy with posterior interbody fusion. PLIF (22630 and 22633) have CCI edits with the various decompression codes as shown in Table2. These edits have a modifier indicator “1” which allows laminectomy (63047) with PLIF (22630) under certain circumstances. This would include laminectomy at a different anatomic site (PLIF at L4/5 and laminectomy L3) similar to the examples given above for 63047 and 63030. In addition, there are circumstances when these codes (63047 and 22630) can be used at the same level.  CPT defines 22630 as “arthrodesis including laminectomy/discectomy to prepare interspace (other than for decompression). If after performing the PLIF, there is remaining stenosis requiring further decompression (extensive canal stenosis requiring complete laminectomy) it would be appropriate to also code the laminectomy (a separate, distinct procedure at the same level identified with modifier 59) according to CPT rules. However, CMS payment policy (Chptr VIII, section C, paragraph 25) does not allow payment of 63042 or 63047 with 22630 or 22633 as it considers the laminectomy/discectomy inclusive of the PLIF.  It's worth noting modifier 59 does not require a different ICD for each CPT; conversely, different diagnosis is not adequate criteria for use of 59.

In January 2015 CMS, introduced modifiers XE, XS, XP, XU to replace modifier 59. These modifiers were developed to provide more specificity in cases where modifier 59 was previously reported. CMS provides the following 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 a 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”

CMS provided few guidelines to the use of these new modifier subsets and since January 2015, CMS has given instructions to continue using Modifier 59. Each MAC, however, may have its own guidelines and instructions for the use of modifier 59. Stay Tuned…


In summary, Modifier 59 is used to indicate a service that is a distinct and separate procedure from another service with which it usually would be “bundled” together. It is used when there is a different session, different procedure/surgery, different anatomic site or organ, separate incision/excision, or separate lesion or injury. It has become the most commonly used modifier and CMS has clearly communicated its concern that Modifier 59 is inappropriately used to “bypass NCCI edits,” resulting in coding errors, abuse, and even civil fraud. CMS opines it should only be used if an NCCI edit exists although this is not a CPT rule. Modifier 59 should only be used when no more descriptive modifier is available and modifier 59 best explains the circumstances. The appropriate use of modifier 59 is an unusual circumstance and for these reasons, likely to result in documentation requirements and possible audit.



 Column1 Column2 Effective Date Delete Date

0 not allowed
1 allowed
9 not applic

PTP edit rationale
63047 62319 20010701 * 0 Anesthesia service included in surgical procedure
63047 63005* 19960101 * 1 Mutually exclusive procedures
63047 63012* 19960101 * 1 Mutually exclusive procedures
63047 63015 19970101 * 1 Mutually exclusive procedures
63047 63017 19970101 * 1 Mutually exclusive procedures
63047 63020 19970101 * 1 HCPCS/CPT procedure code definition
63047 63030 19960101 * 1 HCPCS/CPT procedure code definition


 Column1 Column 2 Effective Date Delete Date

0 not allowed
1 allowed
9 not applic

PTP edit rationale
22630 63030 19990101   1 Standards of medical / surgical practice
22630 63042 20140101 * 1 Misuse of column two code with column one code
22630 63047 19990101 * 1 Misuse of column two code with column one code

Chair: Mathew D. Hepler, MD Committee: Christopher J. DeWald, MD; Nigel J. Price, MD; Samuel S. Bederman, MD, PhD, FRCSC; Shay Bess, MD; Barton L. Sachs, MD, MBA, CPE; Michael S. Chang, MD; R. Dale Blasier, MD; Richard J. Haynes, MD