Understand Modifier 59 and NCCI Bundling

Double dipping is a risk if you don’t know the rules.

By Angela Clements, CPC, CEMC, COSC

Modifier 59 Distinct procedural service is used when two codes are not normally reported together (for instance, one code may be bundled with the other), but may be billed together under certain circumstances (for instance, if the two procedures occurred at different anatomic locations). 

Modifier 59 is the “modifier of last resort” because you should append it only when no other modifier is more appropriate (e.g., modifiers to describe laterality, such as LT, RT, and 50; or coronary modifiers such as LC, LD, LM, RC, RI, etc.), and documentation supports a distinct or independent service.

Examples of a distinct or independent service may include:

  • Different session
  • Different procedure or surgery
  • Different site or organ system
  • Separate incision/excision
  • Separate lesion
  • Separate injury

Source: CPT® codebook, Appendix A.

Beware of Exceptions!

If two polyps are removed — for example, one from the ascending colon and one from the descending colon — via cold biopsy, the removals are reported using one CPT® code, 45380 Colonoscopy, flexible, proximal to splenic flexure; with biopsy, single or multiple, even though the lesions were in different locations.

If a bone marrow biopsy and aspiration are performed at two sites through the same incision, report only 38221 Bone marrow; biopsy, needle or trocar. Do not additionally report 38220 Bone marrow; aspiration only with modifier 59. Note that Medicare has created G0364 Bone marrow aspiration performed with bone marrow biopsy through the same incision on the same date of service, which you may report in addition to 38221 when a bone marrow biopsy and aspiration are performed through the same incision. Check with private insurance companies to verify if they recognize this code.

Avoid Indiscriminate Modifier 59 Use

The Centers for Medicare & Medicaid Services (CMS) developed the National Correct Coding Initiative (NCCI) to promote correct coding and prevent improper payments. The edits are updated quarterly. Unfortunately, modifier 59 is often used incorrectly to bypass NCCI edits. Examples of such inappropriate use include:

  • Appending modifier 59 to a diagnostic procedure performed prior to a scheduled therapeutic procedure, when the basis for the diagnostic procedure did not lead to the decision for the therapeutic procedure
  • Appending modifier 59 to a diagnostic procedure performed following a therapeutic procedure, when the diagnostic procedure is considered a component of the therapeutic procedure
  • Appending modifier 59 to a claim just because the service was denied as a bundled service

Because modifier 59 lends itself to misuse (and abuse), the Office of Inspector General recommends that CMS perform pre- and post-payment reviews on claims submitted with modifier 59. To ensure your claims are clean, it helps to understand how NCCI edits work.

Finding and Interpreting NCCI Code Pair Edits

Access NCCI data free on the CMS website. Scroll down to “Related Links” and choose the Physician coders or Hospital (facility coders) coding edit link that represents the code range in which you are reviewing. This allows you to download several files.

Within the Excel spreadsheet containing the NCCI code pairs, there are two columns of codes, as well as an indicator column. The Column 2 code is either a component of Column 1 or mutually inclusive and not separately reportable from the code in Column 1, as shown in Table 1. When allowed and appropriate, a modifier is appended to the Column 2 code. To determine if the modifier is allowed, you must know the meaning of the modifier indicators, as shown in Table 1.

Modifier Indicator Definition

(Not Allowed)

There are no modifiers associated with NCCI that are allowed to be used with this code pair; there are no circumstances in which both procedures of the code pair should be paid for the same beneficiary on the same day by the same provider.


The modifiers associated with NCCI are allowed with this code pair when appropriate.

(Not Applicable)

This indicator means that an NCCI edit does not apply to this code pair. The edit for this code pair was deleted retroactively.

For example, consider the NCCI code pair edit in Table 2. In the case of this code pair, a modifier is allowed. To know when it’s appropriate to apply a modifier, follow guidelines for the modifier being considered. For example, if you are using modifier 59, does the documentation state the biopsy and aspiration were performed at different anatomic sites? Were they performed through two separate incisions? Were they performed at two different encounters?

Column 1 Column 2 * = In existence prior to 1996 Effective Date Deletion Date
* = no data
0 = not allowed
1 = allowed
9 = not applicable
38221 38220   20020101 * 1

If the answer is “yes” to any of these questions, you can apply modifier 59 to 38220 (the Column 2 code).

Example 1:

An orthopedic surgeon performs arthroscopic medial and lateral meniscus repair, 29880 Arthroscopy, knee, surgical; with meniscectomy (medial and lateral, including any meniscal shaving) including debridement/shaving of articular cartilage (chondroplasty), same or separate compartment(s), when performed, along with arthroscopic chondroplasty in the patellofemoral. Note, however, that meniscus repair (29880) includes chondroplasty (29877 Arthroscopy, knee, surgical; debridement/shaving of articular cartilage (chondroplasty)), even if performed in a separate compartment. The code pair has been assigned an NCCI indicator of “0,” and it would not be appropriate to bill both codes or to append modifier 59 in this scenario. You would report only 29877.

Example 2:

A general surgeon removes two skin lesions from a patient’s left forearm. The lesions are 0.5 cm apart. Both lesions are 1 cm and are removed with margins of 0.5 cm. The physician makes one incision, removing both lesions. The pathology report returns as benign. The correct code is 11404 Excision benign lesion including margins, except skin tag (unless listed elsewhere), trunk, arms, or legs; excised diameter 3.1 to 4.0 cm. The physician did remove two distinct lesions; however, they were removed through one incision. The length of the two lesions is added together (1 cm + 1 cm, plus the 0.5 distance between the two lesions and 1 cm for the margins on each side of the incision), equaling 3.5 cm.

If the physician had removed the two lesions using two separate skin incisions, you would report instead 11402 Excision benign lesion including margins, except skin tag (unless listed elsewhere), trunk, arms, or legs; excised diameter 1.1 to 2.0 for the first lesion (1cm lesion + 0.5 cm margin on each side) and 11402-59 for the second lesion.

Example 3:

A patient is sent to the cath lab for a diagnostic left heart catheterization (LHC) with ventriculogram. During the diagnostic cath procedure, the physician determines the extent of blockage requires a stent placement in the left anterior descending artery and the right coronary artery. A diagnostic LHC, 93458 Catheter placement in coronary artery(s) for coronary angiography, including intraprocedural injection(s) for coronary angiography, imaging supervision and interpretation; with left heart catheterization including intraprocedural injection(s) for left ventriculography, when performed, is a Column 2 NCCI edit to the stent, 92928 Percutaneous transcatheter placement of intracoronary stent(s), with coronary angioplasty when performed; single major coronary artery or branch. The documentation supports the guidelines to bill a LHC and stent placement on the same day. Modifier 59 is appended to the diagnostic LHC 93458 (because it’s the Column 2 code). The surgeon placed two stents in two distinct recognized arteries, which means you should apply coronary modifiers. Correct coding is 92928-LD Left anterior descending coronary artery and 92928-RC Right coronary artery.

Note: Know your payer guidelines. Some payers will require modifier 59 on the second stent code, 92928, to indicate separate arteries, even when billed with the coronary modifiers.

Helpful Modifier 59 Tips

  • A different diagnosis is not needed to append modifier 59.
  • A different diagnosis doesn’t automatically qualify a code for modifier 59 if the above criteria have not been met.
  • Modifier 59 should never be used to simply bypass an edit when the above criteria have not been met.
  • Modifier 59 is appended to the Column 2 code in the NCCI table.
  • Modifier 59 is not an evaluation and management modifier.
  • Make sure your physician documents everything clearly. For example, “A separate incision was made,” “A different modality was used to remove the polyp,” “Patient was brought back to the operating room,” etc.
  • Read the documentation. Do not append modifier 59 simply because your software’s edit states to add modifier 59.

Angela Clements, CPC, CEMC, COSC, is a manager in the Revenue Cycle, Integrity, Auditing and Analytics Department at St. Tammany Parish Hospital in Covington, La., with 16 years of healthcare experience in multi-specialty coding. She is a member of the AAPC National Advisory Board for Region 5 and president of the Covington, La., local chapter.


Renee Dustman

Renee Dustman

Renee Dustman is executive editor at AAPC. She has a Bachelor of Science degree in Journalism and a long history of writing just about anything for just about every kind of publication there is or ever has been. She’s also worked in production management for print media, and continues to dabble in graphic design.
Renee Dustman

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About Has 419 Posts

Renee Dustman is executive editor at AAPC. She has a Bachelor of Science degree in Journalism and a long history of writing just about anything for just about every kind of publication there is or ever has been. She’s also worked in production management for print media, and continues to dabble in graphic design.

2 Responses to “Understand Modifier 59 and NCCI Bundling”

  1. Wilma Soto says:

    I am a Spanish speaker medical biller. I had worked with a spinal orthopedic surgeon for the last 7 years. Finishing 2015 and beginning 2016 , I confronted many doubts. I don’t understand why medicare is not paying cpt 20931 in lumbar fusion and decomp neither cervical fussion. I understand that the reason is because I am billing 22851 with it, that what the doctor told me. Could I use another cpt as 20930? Some medicare advantages plans are not paying 22633 with 63047 modif 59 and its addon 63048. I bill these in a lumbar fusion and decompression surgery. Could you help me ?

  2. ASaiz says:

    Thank you for your comment. You’ll find a lot of suggestions and better answers to your question in the Member Forums.

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