Billing Guideline for ASC unilateral services

Unilateral Services

When a procedure is performed unilaterally, and the procedure description in CPT® states “bilateral”, the service shall be identified with a modifier 52.

The reimbursement amount shall be the contractual amount if the contract was written for a bilateral procedure description that is being performed unilaterally. If the agreed upon contract amount was for a bilateral procedure that was contracted to be performed bilaterally, but the procedure was performed unilaterally, reimbursement shall be fifty percent (50%) of the contracted amount.
If there is no contracted amount, reimburse fifty percent (50%) of the MRA, if the procedure code is listed in Chapter 5, or fifty percent (50%) of seventy percent (70%) of billed charges, if the procedure code is not listed in Chapter 5.

Note: If the procedure code is not the primary procedure code, the amount determined pursuant to this section shall be used under Multiple Surgical Procedure Reimbursement Amount, earlier in this Chapter, as the amount under items 3, or 4, as applicable therein, unless the procedure code is not listed in Chapter 5, in which case, fifty percent (50%) of the amount determined pursuant to this section shall be used under item 2, therein.

Billing Bilateral Procedures Performed with Other Surgical Services
If bilateral surgical procedures are performed during the same operative session with other surgical services:

• Bill the primary surgical procedure code on the first line using no modifier 51.

• Bill the additional surgical procedure code(s) using modifier 51 to indicate multiple procedures performed during the same operative session.

• Bill the bilateral procedure using modifier 50 in the first modifier position, where appropriate. Then bill modifier 51 in the second modifier position.