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Modifier 50

Modifier 50 is defined as a bilateral procedure performed on both sides of the body and is used to report bilateral procedures performed during the same operative session as a single line item. 

When submitting claims for bilateral surgery, use modifier 50 with the procedure code. Services will be rejected as unprocessable when the procedure code reported is inconsistent with the modifier used. 

Appropriate use

  • Claims for bilateral surgical procedures should be billed on a single claim detail line with the appropriate procedure code and modifier 50 and one (1) unit of service (UOS).
  • If more than one bilateral procedure was performed, the number of units should be adjusted to reflect the number of bilateral procedures that are performed.
  • When billing claims for procedure codes that are bilateral in nature, regardless of whether these services are performed unilaterally or bilaterally, providers should bill the surgical procedure code as a single claim detail line item without modifier 50.

Example

A mastectomy, CPT code 19303 (Mastectomy, simple, complete), is performed bilaterally.

Correct coding

Date of service Procedure code Modifier Units
6/1/2024 19303 50 1

 

Incorrect coding

Date of service Procedure code Modifier Units 
6/1/2024 19303 LT 1
6/1/2024 19303 RT 1

Inappropriate usage

  • To report surgical procedures identified by their terminology as "bilateral".
  • To report surgical procedures identified by their terminology as "unilateral or bilateral," regardless of whether the procedure is performed bilaterally or not.
  • Do not append to procedures for midline organs such as the bladder, uterus, esophagus, or nasal septum.
  • Inappropriate to report when performed on different areas of same side of body.
  • Modifier 50 cannot be appended when bilateral indicators are 0, 2, 3 or 9. (*)
  • Modifier 50 cannot be appended to an add on code.
  • Do not use modifiers RT and LT when modifier 50 applies.
  • Do not submit two separate line items to report a bilateral procedure using modifier 50.

Example 

The terminology for CPT code 27158 (osteotomy, pelvis, bilateral) indicates the procedure is performed bilaterally. Therefore, it's not appropriate to report modifier 50 with this procedure code.

Bilateral surgery indicators (*)

  • "0" indicates a unilateral code; modifier 50 is not billable.
  • "1" indicates modifier 50 can be appropriate.
  • "2" indicates a bilateral code; modifier 50 is not billable.
  • "3" indicates primary radiology codes; modifier 50 is not billable.
  • "9" indicates the concept does not apply.

Medically unlikely edits (MUE) and bilateral procedures

When reporting bilateral surgical procedures that have an MUE adjudication indicator (MAI) of "2" or "3", bill with modifier 50 and one unit of service.

Ambulatory surgical centers (ASCs) and modifier 50

ASC specialty providers don't report modifier 50. 

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.
  • Claims inappropriately billed by ASCs with a modifier 50 will be rejected.

Bilateral procedures should be reported:

  • Single unit on two separate lines or a single unit on one line with "2" in the unit field, for both procedures to be paid correctly.
  • Multiple procedure reduction of 50% will apply to all bilateral procedures subject to multiple procedure discounting.

Additional information

Multiple surgery pricing applies to bilateral services (modifier 50) performed on the same day with other procedures. 

To determine if a procedure should be billed with the modifier 50 as a bilateral procedure, providers may access the Medicare Physician Fee Schedule (MPFS) look-up tool. Select MPFS, enter the procedure code, date of service and locality. Once you select "Submit," the details relating to the procedure code will be revealed. Under the heading "Modifier," scroll to the “Policy Indicator” section. The "Bilateral Surgery" indicator will advise if a modifier 50 should be billed with the code. 

For additional information, please access the change request (CR) 8853

 

References