Most asked question on Modifier 50, 59, 79

Q: When is it appropriate to bill modifier 50?

A: Modifier 50 is used to report bilateral procedures performed during the same operative session as a single line item. Do not use modifiers RT and LT when modifier 50 applies. Do not submit two line items to report a bilateral procedure using modifier 50.

When submitting claims for bilateral surgery, use modifier 50 with the procedure code. Modifier 50 applies to any bilateral procedure performed on both sides at the same operative session, except as indicated below. The bilateral modifier 50 is restricted to operative sessions only.

Modifier 50 may not be used:

• To report surgical procedures identified by their terminology as "bilateral," or

• To report surgical procedures identified by their terminology as "unilateral or bilateral," regardless of whether the procedure is performed bilaterally or not.

• 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.

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).

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 date of service, locality and procedure code. Once you select "Submit," the details of the procedure code will be revealed. Under the heading "Modifier," select more. The "Bilateral Surgery" indicator will advise if a modifier 50 should be billed with the code.

Q. How is modifier 59 used when billing Medicare?

A. Modifier 59 is used to indicate a distinct procedural service.

• Under certain circumstances, the physician or provider may need to indicate that a procedure or service was distinct or independent from other services performed on the same day.

Modifier 59 is used to identify procedures or services that are not normally reported together, but are appropriate under the circumstances. Modifier 59 should be reported in the following circumstances:
• When relative to another procedure or service performed the same day, a procedure involves a:

1. Different session or patient encounter.
2. Different procedure or surgery.
3. Different body site or organ.
4. Separate incision or excision.
5. Separate lesion.
6. Separate injury (or area of injury in extensive injuries).

• When the procedure or service performed is independent from other services performed on the same day
• When the procedures or services are not normally reported together.
• When no other modifier best explains the circumstances


A physician performs a simple repair (2.5 centimeters in size) of a superficial wound to the right arm and also performs a partial thickness skin debridement of another site on the same arm.

The above example should be reported on the claim with the following CPT codes:

• 12001 (covers the repair of the superficial wound) and
• 11040-59 (covers skin debridement)

Q: What is the meaning of modifier 79 and how is it properly applied when submitting claims?

A: Per the Current Procedure Terminology (CPT) ® manual, the descriptor of modifier 79 is:
• “Unrelated procedure or service by the same physician during the postoperative period.”

As indicated, this modifier is used to bill an unrelated procedure or service by the same physician during the postoperative period of a previous surgical procedure.

When a patient has surgery performed, there is a postoperative period -- a period after the surgery has been performed when additional surgical care related to the initial surgery is considered already covered (and paid for) by the allowance provided for the initial surgery. The postoperative period can be zero or 10 days (minor surgical procedure) OR 90 days (major surgical procedure). (Note that some surgeries are considered so minor that they have a zero (0) day postoperative period, usually a very quick outpatient procedure.)

Modifier 79 should be used when a surgical procedure is:

• Performed during the postoperative period, where the original surgery had a global period of 10 or 90 days.
• Performed by the same physician or physician of the same specialty within the same group, and
• Unrelated to the original surgical procedure

Note: When the 79 modifier is used, a new postoperative period for the second surgical procedure begins. Additionally, the remainder of the postoperative period of the original surgery is still applicable.


  1. i have 2 questions. one is when i bill an e/m code with 99000 do i need a modifier? also when i am billing an e/m code with 11055 along with g0127 what modifier do i use for the 11055.i have been getting paid on g0127 with a q8 and 51 modifier but what ever i use for the 11055 denies. please advise

  2. my question is can you bill 93923 with 59 modifier for two units? Why are we getting denied through Medicare. Can we use the modifier 50


Most read cpt modifiers