Optometry Coding & Billing Alert

Question: Our office is considering purchasing an OCT instrument. What does the machine do, and how should we code and bill for it? What's the Medicare allowable for the service?


Washington Subscriber


Answer: OCT stands for optical coherence tomography; it's also sometimes called a retinal thickness analyzer (RTA).

Optometrists use OCT as an early test for eye disease, especially glaucoma.

Code OCT with 92135 (Scanning computerized ophthalmic diagnostic imaging [e.g., scanning laser] with interpretation and report, unilateral). Use this same code to report all scanning laser glaucoma tests (SLGT).
 
The test is inherently unilateral. If the optometrist tests both eyes, report 92135 bilaterally--either on two lines with modifiers RT (Right side) and LT (Left side) appended, or on one line with modifier 50 (Bilateral service) appended.

In the 2005 Physician Fee Schedule, 92135 has 1.16 total RVUs assigned to it. Multiply this amount by the conversion factor (37.8975) to see the base total Medicare reimbursement: $43.96.

Medicare carriers use geographic practice cost index (GPCI) numbers to calculate reimbursement in specific localities. They break the total RVUs down into RVUs for work, practice expense and malpractice and multiply each figure by a different GPCI for that region.
 
Example: In most of Washington state, Noridian pays for 92135 based on these figures:

Component                   RVUs x GPCI                          = Total
Work                              0.35 x 1                                  = 0.35
PE                                 0.79 x 0.975                            = 0.77
MP                                 0.02 x 0.819                            = 0.016
Total RVUs (1.136) x 37.8975                                         = $43.05

Easier way: You can look up payments for individual codes for your locality on the CMS Web site at http://www.cms.hhs.gov/physicians/mpfsapp/step0.asp.

Warning: NCCI bundles 92135 with 92250 (Fundus photography with interpretation and report). Unless there is a medical necessity, you cannot bill for both procedures on the same day.