Question: Missouri Subscriber Answer: Don't report 92100 just because the ophthalmologist performed tonometry once or twice during an eye exam. Medicare and CPT both consider tonometry incidental to an intermediate or comprehensive exam for a new or established patient (92002-92014) or E/M service. This is true even if the ophthalmologist repeats the tonometry. The ophthalmologist may not perform all of the serial tonometry tests in the same day, but even if he spreads the test out over several days, you can still report 92100 only once. Medicare considers the procedure bilateral, so only code it once whether the physician tests one or both eyes. -- Advice for You Be the Coder and Reader Questions provided by Maggie M. Mac, CMM, CPC, CMSCS, consulting manager for Pershing, Yoakley and Associates in Clearwater, Fla.