Ophthalmology and Optometry Coding Alert

Coding strabismus surgery requires understanding the muscle anatomy. In each eye, there are two horizontal muscles (one on the nasal side, and one on the temporal side), two vertical muscles (one on the top, and one on the bottom), and two oblique muscles (called superior and inferior).
 
Because of muscle placement, strabismus coding is particularly confusing when multiple procedures are performed. Bilateral means the same muscle in each eye, not two muscles on opposite sides of the same eye. The nasal and temporal horizontal muscles in one eye do not constitute a bilateral procedure. However, a horizontal muscle in the left eye and a horizontal muscle in the right eye do. 
Horizontal Muscles
For surgery on one horizontal muscle in one eye, report CPT 67311 (strabismus surgery, recession or resection procedure; one horizontal muscle). For surgery on both horizontal muscles in the same eye, use 67312 ( two horizontal muscles).
 
When surgery is performed on one horizontal muscle in the left eye the lateral (temporal side) rectus muscle or the medial (nasal side) rectus muscle and the lateral rectus or medial rectus muscle in the right eye, code the single horizontal muscle on each eye on two lines: 67311 and 67311-50 (bilateral procedure) or 67311-RT (right side) and 67311-LT (left side). Do not use 67312 for this procedure.
 
Code 67312 is appropriately valued lower than 67311 billed bilaterally. Reporting 67312 for 67311 bilaterally is improper coding that will cost reimbursement, says Lise Roberts, vice president of Health Care Compliance Strategies, a CD-ROM-based compliance training firm in Jericho, N.Y.
Vertical Muscles
If one vertical muscle the superior rectus or inferior rectus is operated on, report 67314 ( one vertical muscle [excluding superior oblique]). If two vertical muscles are operated on in the same eye, use 67316 ( two or more vertical muscles [excluding superior oblique]).
 
"Two or more vertical muscles" might lead one to believe that this is a bilateral code. There are technically only two vertical muscles in one eye, but CPT considers the inferior oblique muscle a vertical muscle for coding purposes.
 
The superior oblique muscle has its own code, 67318 (strabismus surgery, any procedure, superior oblique muscle).
 
Medicare views 67316 as unilateral, and therefore expects 67316 to be billed twice when operating on two or more vertical muscles on each eye. For example, use 67316 when both vertical muscles in one eye are treated, but when a single vertical muscle is treated in each eye code on two lines:

 Line 1: 67314 (or 67314-RT)
 Line 2: 67314-50 (or 67314-LT).
If a single vertical muscle is operated on in one eye and two or more vertical muscles are operated on the other, report 67316 -RT or -LT for the first eye and 67314 [...]