Ophthalmology and Optometry Coding Alert

Question: What is the proper way to code when the same procedure -- strabismus surgery -- is done on the same muscle on both eyes? Should we use modifier -50 when billing Medicare? How should I code for the same procedure, on the same muscles, on each eye during only one session?

Florida Subscriber

Answer: The proper way to code for strabismus surgery done on both eyes for most Medicare carriers is to report the procedure code with modifier -50 (Bilateral procedure) and a "1" in the units field.

Let's say an ophthalmologist performs strabismus surgery on two horizontal muscles - one in the left eye and one in the right eye.

The correct code is 67311, not 67312. Here is the difference: 67311 is for strabismus surgery, recession or resection procedure; one horizontal muscle, while 67312 is for strabismus surgery, recession or resection procedure; two horizontal muscles. Coders who use 67312 when the doctor has done the procedure in two eyes are making an understandable error: CPT does say two muscles. Each strabismus code, however, is per eye only.

Don't add up the muscles done in two eyes and use a code that is meant for one eye. Not only is this inaccurate coding, but you'll hurt your reimbursement. If the ophthalmologist performs strabismus surgery on two horizontal muscles in the left eye and one horizontal in the right eye, don't use modifier -50.

Use modifier -50 only when the same procedure, represented by the same procedure code, is performed. Instead, you would put 67312-LT on the first line and 67311-RT on the second line.

Payers' policies on how to code for strabismus performed in both eyes in one session will vary. Although most Medicare carriers want you to report the entire session on one line with modifier -50 and a "1" in the units field, Medicaid often prefers two lines with modifier -50 on the second line.

Managed-care plans vary in terms of their requirements, so you need to find out how they want it to be filed. And indemnity plans -- the few that are left -- most often require you to use alpha modifiers, so you would use 67311-LT on the first line and 67311-RT on the second line.