Modifier 51: Appropriate Use

September 5, 2020Modifiers

Modifier 51: Multiple Procedure

CPT guidelines explain the 51 modifier should apply when ‘multiple procedures, other than E/M services, are performed at the same session by the same individual.’ The additional procedure(s) or service(s) may be identified by appending this modifier to the additional procedure or service code(s). For this modifier, appropriate coding must take into consideration the RVU (relative value units) of the performed CPTs in order to be billed effectively.

Multiple surgeries performed on the same day, during the same surgical session.
Diagnostic Imaging Services subject to the Multiple Procedure Payment Reduction that are provided on the same day, during the same session by the same provider.

In other words, modifier 51 reports that a physician performed two or more surgical services during one treatment session. The modifier would be applied to any secondary procedures performed. But with modifier 51, qualifications for the “primary” procedure code may be different from what you know about the use of other modifiers. To report this modifier correctly, the coder should list the procedure with the highest RVU (highest paying) first, and use the modifier on the subsequent service(s) with lower RVU (lowest paying).

Medicare no longer requires modifier 51, as their internal systems are programmed to add 51 internally to the correct procedure code(s), and make the appropriate reductions to the remaining services billed. Many payers follow suit to the standards of Medicare, so it is evident that with modifier 51, knowing what payer requirements are in your area will be key to appending modifier 51 correctly avoiding unnecessarily denied claims.

Appropriate Use

Modifier 51 is appended when

the same physician performs more than one surgical service at the same session (Indicator 2).
the technical component of multiple diagnostic procedures, Multiple Procedure Payment Reduction (MPPR) rule applies (Indicator 4).
the multiple surgical procedures are done on same day but billed on two separate claims.
the surgical procedure code is the lower physician fee schedule amount.
the diagnostic imaging procedure with the lower technical component fee schedule amount.

Example of Modifier 51

A dermatologist performs an excision of a malignant skin lesion. During the patient’s treatment, a separate skin lesion is discovered which the physician thinks warrants closer attention. After obtaining consent from the patient to perform a second procedure, the physician performs a biopsy of the new site. To bill correctly and appropriately, the coder would list the surgical services rendered as follows:

12031 (wound closure)
11600-51 (excision of malignant lesion
11100-51 (biopsy of skin, single lesion)

This is a good illustration of where our coding assumptions and the coding rules go their separate ways. Many billing and coding staff would think the excision should be indicated as the primary procedure, since it is the reason the patient obtained treatment. But with modifier 51 being dependent upon procedure cost, we find that the closure (highest cost) should be billed as primary, with the second and subsequent procedures of the excision and biopsy (lower cost) needing modifier 51.

Inappropriate Use

Do not append to add-on codes (See Appendix D of the CPT manual)
Do not report on all lines of service
Do not append when two or more physicians each perform distinctly, different, unrelated surgeries on the same day to the same patient.

Additional Information

Medicare pays for multiple surgeries by ranking from the highest physician fee schedule amount to the lowest physician fee schedule amount.
- 100% of the highest physician fee schedule amount
- 50% of the physician fee schedule amount for each of the other codes
Medicare will forward the claim information showing Modifier 51 to the secondary insurance.
Multiple surgery pricing also applies to assistant at surgery services.
Multiple surgery pricing applies to bilateral services (modifier 50) performed on the same day with other procedures.

Understanding the correct and appropriate use of modifier 51 will be key to filing correct claims, which will then result into accurate payment. Not only does the 51 modifier allow us to code physician services to the highest level of specificity possible, but it ensures the physician is paid accordingly for those services. However, it’s important to stay aware of the most current payer guidelines for appending modifiers, particularly modifier 51. Rules for applying the 51 modifier may vary depending on your state or locale, so it’s advisable to stay informed of any upcoming changes in payer requirements in order to maintain claims approvals and healthy revenue flow for your practice.

Still not sure about the appropriate use of Modifier 51? Don’t worry E2E Medical Billing Services has an experienced coding team that uses exact modifiers to avoid denials. To know more about our medical billing services call us at 888-552-1290 or write to us at info@e2eMedicalBilling.com