Modifier 50: Appropriate Use

Modifier 50: Bilateral Procedure
Modifier 50 is used to report bilateral procedures that are performed during the same operative session by the same physician in either separate operative areas (e.g. hands, feet, legs, arms, ears), or one (same) operative area (e.g. nose, eyes, breasts). The current coding manual states that the intent of this modifier is to be appended to the appropriate unilateral procedure code as a one-line entry on the claim form indicating the procedure was performed bilaterally (two times).
When using Modifier 50 to indicate a procedure was performed bilaterally, the modifiers LT (Left) and RT (Right) should not be billed on the same service line. Modifiers LT or RT should be used to identify which one of the paired organs were operated on. Billing procedures as two lines of service using the left (LT) and right (RT) modifiers is not the same as identifying the procedure with Modifier 50. Modifier 50 is the coding practice of choice when reporting bilateral procedures.
Appropriate Usage
- When performing a procedure bilaterally during one session and the Medicare Physician Fee Schedule BILAT SURG indicator is 1:
- Report codes with a BILAT SURG indicator of 1 on one line, appending modifier 50, and submit one unit of service. (this differs from Current Procedural Terminology (CPT) instruction.)
- When performing a procedure bilaterally during one session and the Medicare Physician Fee Schedule (MPFS) BILAT SURG indicator is 3:
- Submit codes with a BILAT SURG 3 on one line appending either modifier 50 using one unit of service (UOS); or
- Submit codes on one line with two UOS (the use of the RT/LT modifiers would be optional); or
- Submit on two lines of service using RT on one line and LT on the other with one UOS each.
Inappropriate Usage
- Reporting this modifier when performing the service on different areas of the same side of the body.
- The BILAT SURG indicator is 0, 2, or 9.
- When removing a lesion on the right arm and one on the left arm – use the RT and LT modifiers.
- Do not use modifier 50 for multiple procedures on one organ, such as the skin.
- On a procedure code that is described as bilateral or unilateral or bilateral in its CPT description.
- Do not report a bilateral procedure on two lines of service appending modifier 50 to the second line of service.
Additional Information
Generally speaking, the above information applies when two of the same procedure codes are performed on the same day for the same patient by the same provider. However, there could be instances where two separate procedure codes are used. If so, insurance reimbursement or denial would depend on any other type of rules or regulations concerning the individual services in question. This could include the National Correct Coding Initiative (NCCI) that could necessitate additional modifiers, duplicate edits, and global surgery edits.
Modifier 50 is used as payment, rather than the informational, modifier. The addition of this modifier could affect payment depending on the procedure code and the BILAT SURG indicator. The BILAT SURG indicator for each procedure code can be found on the Medicare Physician Fee Schedule Relative Value File. The following are the indicators and their descriptions:
Bilateral Indicator 0
- Bilateral surgery rules do not apply to codes with a status indicator 0. The bilateral indicator is inappropriate for reasons such as:
- Physiology; is not a bilateral body part.
- The code description states it is an existing bilateral procedure.
- The procedure is not commonly performed as bilateral. (These services do not meet the bilateral criteria.)
- These codes should not be billed with modifiers 50, LT, or RT.
- The 150 percent payment adjustment for bilateral procedures does not apply.
Bilateral Indicator 1
Valid for bilateral billing claim submission. With the exception of CPT codes inherently bilateral by definition, payers require practitioners to report procedures performed bilaterally on one claim line with modifier 50 appended to the code (e.g., XXXX-50, billed with 1 unit). Failure to report bilateral procedures in this way may result in incorrect processing of claims.
Reporting these bilateral-indicator-1 procedures with either LT or RT and 1 unit of service is appropriate only if the procedure is being performed unilaterally. If the procedure is performed bilaterally, modifier 50 should be appended to the procedure code with 1 unit of service. The 150 percent payment adjustment for bilateral procedures applies.
Bilateral Indicator 2
These codes should not be billed with modifier 50. These codes are already established as being performed bilaterally:
- The code descriptors specifically state the procedure is bilateral.
- The code descriptor states the procedure may be performed either unilaterally or bilaterally.
- The procedure is usually performed as bilateral.
- These codes should be billed with no more than 1 unit of service
Reporting these procedures with either an LT or RT modifier is appropriate if no unilateral CPT code exists. If a unilateral CPT code exists for the procedure, the unilateral CPT code should be reported with either the LT or RT modifier, with 1 unit of service. If no unilateral CPT code exists, modifier 52 should be appended to the bilateral CPT code to indicate a reduced service was performed. The 150 percent payment adjustment for bilateral procedures does not apply.
Bilateral Indicator 3
These codes should be reported with the appropriate anatomical LT or RT modifier, with one unit of service for each. For example:
- xxxxx-LT billed with 1 unit on one claim line
- xxxxx-RT billed with 1 unit on a separate claim line
A practitioner can submit with modifier 50 if performed bilaterally. The usual payment adjustment for bilateral procedures does not apply.
Bilateral Indicator 9
Concept does not apply. Bilateral surgery concept does not apply to codes with status indicator 9. These procedure codes should not be billed with modifiers 50, LT or RT (e.g., xxxxx, billed with 1 unit).
Ambulatory Surgical Centers (ASCs) and Modifier 50
- Modifier 50 is not recognized for payment purposes for ASC procedures. When more than one surgical procedure is performed in the same operative session, multiple surgery rules apply:
- Medicare will allow 100% of the highest paying surgical procedure on the claim plus 50% for the other ASC-covered surgical procedures furnished in the same session.
- Bilateral procedures should be reported:
- A single unit on two separate lines or a single unit on one line with “2” in the unit field, in order for both procedures to be paid correctly.
- Multiple procedure reduction of 50% will apply to all bilateral procedures subject to multiple procedures discounting.
Modifiers © Copyright 2021 American Medical Association
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