Modifier Coding Alert

Follow Medicare’s rule of thumb when billing for unilateral tests.

If you don’t understand the modifiers that your payers prefer for bilateral tests, your claims may be denied. Looking up the bilateral indicator for your optometry testing codes will help prevent incorrect billing and subsequent claim denials.

Read on to learn where to find the information you need to ensure you are billing every test your provider performs correctly, whether it is a unilateral or bilateral test.

Conquer the Bilateral vs. Unilateral Conundrum

A common cause of denials with your insurance payers, especially Medicare, can be the inappropriate use of modifiers on your diagnostic tests, say experts. Leaving off needed modifiers can also cause underpayment on your claims.

Key: To find out if any CPT® code is bilateral or unilateral, you can check your Medicare fee schedule. You can find the bilateral indicator in column “Z” (“Bilat Surg”) of the Physician Fee Schedule spreadsheet.

Checking this bilateral indicator will help you decide how to properly code the work done to assure you’re correctly paid. The bilateral indicator can tell you whether a CPT® code is billable per eye or only once for both eyes. It can also tell you whether or not you can append modifier 50 (Bilateral procedure) to a CPT® code. If you don’t look at the indicator and you use modifier 50 on a code that you can’t use it on, your claim will be denied, and it may be a little unclear why you’re not getting paid, experts advise.

Tip: You can download the fee schedule spreadsheet from the CMS Web site at www.cms.gov/PhysicianFeeSched/ — or you can look up fee schedule information for individual CPT® codes at https://www.aapc.com/codes/.

Interpret the Fee Schedule for ‘Bilateral’ Answers

The bilateral indicators you’ll find in the Physician Fee Schedule for optometric diagnostic tests are:

Bilateral indicator “2”: Medicare assigns indicator “2” to codes that already specify a bilateral procedure, so you do not need to append a modifier to show that you performed any of these on both eyes. Often, such codes will also specify “unilateral or bilateral” in their CPT® descriptors.

Example: You perform serial tonometry, 92100 (Serial tonometry [separate procedure] with multiple measurements of intraocular pressure over an extended time period with interpretation and report, same day [e.g., diurnal curve or medical treatment of acute elevation of intraocular pressure]), on both of a patient’s eyes. Code 92100 has a bilateral status of “2,” telling you that the work involved in measuring both corneas is already included. So you should report 92100 only once.

Bilateral indicator “3”: You can report codes with bilateral indicators of “3” bilaterally using the appropriate modifier(s). Bilateral indicator “3” indicates that the usual bilateral payment adjustment does not apply.

For many procedures that you report for both sides on the same day, insurance payers will pay 150 percent of the unilateral fee. For procedures marked with bilateral indicator “3,” however, payers will base payment on the fee schedule amount for each side — bringing you 200 percent reimbursement.

Example: You perform extended ophthalmoscopy on both eyes. Code 92225 (Ophthalmoscopy, extended, with retinal drawing [e.g., for retinal detachment, melanoma], with interpretation and report; initial) has a bilateral indicator of “3.” Bill 92225 with modifier 50 (or list it twice with modifiers LT [Left side] and RT [Right side] appended). The payer should pay you twice the amount it would have for a unilateral lens fitting (either the fee schedule amount or your actual fee, whichever is lower).

Bilateral indicator “9”: The concept of bilateral surgery does not apply to codes with this indicator. Therefore, you should never append modifier 50 or modifiers LT/RT in combination to these procedures.

Example: Refraction, 92015 (Determination of refractive state), has a bilateral status of “9” and therefore may never have a 50, RT, or LT appended to it on a claim form. Bill it only once.

Bill Lens Fittings Unilaterally

Two other modifier indicators can give you critical clues for accurate coding of optometric procedures:

Bilateral indicator “1”: You can append modifier 50 to the code.

Example: You perform epilation with forceps on both eyes to correct trichiasis 67820 (Correction of trichiasis; epilation, by forceps only). When you find 67820 in the Physician Fee Schedule database, you’ll notice a “1” in the “Bilat Surg” column, and you can therefore report 67820 and append modifier 50.

Bilateral indicator “0”: Modifier 50 is not allowed. In many cases, bilateral billing is inappropriate for these codes because the code descriptors specifically state that they are unilateral. You may report modifiers LT or RT, however, either in combination or singly, to make your claim more specific.

Example: The fitting of one aphakic lens, 92311 (Prescription of optical and physical characteristics of and fitting of contact lens, with medical supervision of adaptation; corneal lens for aphakia, 1 eye), has a bilateral status of “0” and therefore may never have modifier 50 appended to it on a claim form. To report fitting of aphakic lenses for both eyes, use code 92312 (... corneal lens for aphakia, both eyes).