The Use of Modifier 50

by  Christine Woolstenhulme, QMC QCC CMCS CPC CMRS
Apr 25th, 2016 - Reviewed/Updated Aug 4th

Modifier Review:  Modifier -50

Modifier 50 is used to report a procedure performed bilaterally.  

Example: The patient underwent bilateral tympanostomy with insertion of ventilating tubes.

If you look up the CPT code 69433, you will see it is a unilateral procedure and there are instructions telling you to append modifier -50 if it is performed bilaterally.

Bilateral reporting can be submitted as follows:  69433-50 or 69433-RT, 69433-LT

Before appending any modifiers, be sure to clarify if the procedure is bilateral or unilateral in nature.  If you append -50 or RT/LT to an already bilateral procedure code the insurance company may deny the claim.  

It is important to know the nuances of the insurance companies you are contracted with.  Some will accept either modifier 50 or RT/LT, but there are some that prefer RT/LT over -50 and vice verse.  

Additionally, when posting payment for a bilateral procedure, be sure the insurance actually paid correctly.  Many times the way the insurance paid is an indicator of their preference of either RT/LT or 50 modifiers.  

The insurance should pay benefits on 150% of allowable for bilateral procedures.  If you billed the insurance with modifier 50 and they only pay benefits on 100% of the allowable that is an indicator that they failed to recognize modifier 50.  At this point it would be wise to contact the insurance company, ask them to review the claim and let you know if they prefer modifier 50 or RT/LT.  Make good notes and be sure to share this finding with any others you work with who may bill this insurance company to avoid future issues.