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Avoid the Top 10 Modifier Mistakes – Modifier 51

Matching CPT code with an ICD 10 code, would seem to be a very straightforward process but there are always variations/exceptions to everything. Sometimes, there are related services that the physician is performing, global periods to contend with, etc. Modifiers will clarify extenuating circumstances, which should allow for payment when they otherwise may not. That said, the improper use of modifiers can be the cause of claim denials just as not using a modifier can be. When using modifiers, make sure you clearly understand what the modifier entails.

In this, and the following blogs, we identify 10 of the most commonly misused modifiers to help you become more aware of the issues surrounding them. We’ll help you understand why they are problematic and how you can use them correctly.

Modifier 51

Modifier 51 is defined as multiple surgeries/procedures. Multiple surgeries performed on the same day, during the same surgical session.  Diagnostic Imaging Services subject to the Multiple Procedure Payment Reduction that is provided on the same day, during the same session by the same provider. Medicare doesn’t recommend reporting Modifier 51 on your claim; our processing system will append the modifier to the correct procedure code as appropriate.

How it’s misused: This modifier can be misused in several different ways. First, you can incorrectly apply it when a procedure is more accurately described with an add-on code. Also, you should not use it with an evaluation and management (E/M) service. And finally, you might incorrectly apply it to the wrong procedure, especially if you are billing claims for Medicare.

Inappropriate Usage:

  • 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.

Appropriate Usage:

The Modifier 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, the Multiple Procedure Payment Reduction (MPPR) rule applies (Indicator 4).
  • The multiple surgical procedures are done on the 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 1: A surgeon performs a 24500 (Closed treatment of humeral shaft fracture; without manipulation) and a 23500 (Closed treatment of clavicular fracture; without manipulation). You would apply the multiple procedures reduction to 23500, which is the lower-paying code (a national Medicare facility fee of $228.24 versus $335.88 for 24500) if your payer requires modifier 51.

Example 2: Colonoscopy (45378) performed at the same session as upper endoscopy (43200). Use modifier 51 on the upper endoscopy (43200) because the RVU’s are lower than the colonoscopy (45378). 45378, 43200-51.

Example 3: The patient presents for removal of a 0.5 cm (as measured by CPT guidelines) malignant skin lesion on the trunk. Layered closure of the resulting wound is performed in the same operative session. The appropriate coding will be, 12031 Repair, intermediate, wounds of scalp, axillae, trunk and/or extremities (excluding hands and feet); 2.5 cm or less (typically 100 percent allowed reimbursement*).

11600-51 Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter 0.5 cm or less (typically reduced reimbursement*).

*Dependent on carrier policy. You should also note that a few carriers may automatically order the procedure codes based on that carrier’s fee schedules.

Modifier 51 should be applied to all other codes when multiple non-E/M services are provided at the same session. Modifier 51 can be used with other modifiers, when appropriate, except modifier 50.

FAQs

1. What is Modifier 51 used for?

Modifier 51 is used to indicate that multiple surgeries or procedures were performed by the same physician on the same day during the same session.

2. When should Modifier 51 not be used?

Modifier 51 should not be used for evaluation and management (E/M) services, add-on codes, or when two different physicians perform distinct, unrelated surgeries on the same patient on the same day.

3. How is Modifier 51 often misused?

It is often misused when applied to add-on codes, used for E/M services, or incorrectly applied to the wrong procedure, especially in Medicare billing.

4. Does Medicare require the use of Modifier 51?

No, Medicare advises against reporting Modifier 51 as their processing system automatically applies the modifier to the correct procedure codes.

5. Can Modifier 51 be used with other modifiers?

Yes, Modifier 51 can be used with other appropriate modifiers, except Modifier 50 (bilateral procedures).

6. How do I determine which procedure to apply Modifier 51 to?

Modifier 51 should be applied to the procedure with the lower physician fee schedule or technical component, as per payer guidelines.

7. What is an example of appropriate Modifier 51 usage?

If a colonoscopy (CPT 45378) and upper endoscopy (CPT 43200) are performed in the same session, Modifier 51 should be applied to the upper endoscopy, as it has the lower relative value unit (RVU).

8. What happens if Modifier 51 is applied incorrectly?

Incorrect use of Modifier 51 can result in claim denials or reduced reimbursement.

9. Can Modifier 51 be used for diagnostic imaging services?

Yes, Modifier 51 can be applied to diagnostic imaging services when multiple procedures are performed during the same session, subject to the Multiple Procedure Payment Reduction (MPPR) rule.

10. Why is it important to understand Modifier 51?

Proper use of Modifier 51 ensures correct billing for multiple procedures and avoids denials or underpayments due to improper coding.

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