Radiology Coding Alert

When in doubt, prompt the payer for their preferences.

The CPT^® code set is packed with codes that describe services and procedures that occur on one side of the body or both sides. However, understanding when to append modifier 50 (Bilateral procedure) or the HCPCS Level II modifiers LT (Left side) or RT (Right side) — or all of them — can leave even experienced coders shaking their heads.

Radiology Coding Alert has compiled several frequently asked questions about modifiers 50, LT, and RT to deliver some guidance on these anatomic procedure modifiers.

‘Do I Need a Modifier At All?’

Before you apply any kind of laterality modifier, make sure you read the CPT^® code descriptor very, very carefully. “If the descriptor includes the word ‘bilateral,’ you should probably not append a laterality modifier,” says Kent Moore, senior strategist for physician payment at the American Academy of Family Physicians. So, adding a laterality modifier to 77067 (Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (CAD) when performed) would not only be unnecessary, it would also be incorrect, as the descriptor clearly notes that the procedure is bilateral, and that the procedure involves taking images of both the right and left breast.

‘How Do I Apply Modifier 50?’

A procedure that is not designated as bilateral but can be performed on an anatomic structure that is symmetrical (like the nose or the cheeks) or that is paired (like the arms, legs, ears, or breasts) will need modifier 50 if it is performed on both of those structures. So, “you can apply modifier 50 to 19303 (Mastectomy, simple, complete) if a patient had a double mastectomy,” says Chelle Johnson, CPMA, CPC, CPCO, CPPM, CEMC, AAPC Fellow, billing/credentialing/auditing/ coding coordinator at County of Stanislaus Health Services Agency in Modesto, California.

Payer alert 1: Novitas Solutions, the Medicare Administrative Contractor (MAC) for jurisdictions L and H, tells you not to append modifier 50 “to procedures for midline organs such as the bladder, uterus, esophagus, or nasal septum” (www.novitas-solutions.com/webcenter/portal/MedicareJL/ pagebyid?contentId=00144531).

‘How Do I Apply LT/RT?’

Essentially, you should apply the same thought process to using an LT/RT modifier as you do for modifier 50. Or, to put it another way, “modifiers -LT and -RT should be used whenever a procedure is performed on only one side … [of] paired organs, e.g., ears, eyes, nostrils, kidneys, lungs, and ovaries,” according to the Medicare Claims Processing Manual (www. cms.gov/files/document/chapter-4-part-b-hospital-including-inpatient-hospital-part-b-and-opps-0).

Payer alert 2: Emblem Health follows this LT/RT policy when it tells you “Do not use modifier 50 when removing a lesion on the right arm and a lesion on the left arm. Use the RT and LT modifiers (www.emblemhealth.com/providers/claims-corner/coding/correct-usage-of-modifier-50-and-modifiers-lt-and-rt-for-bilater).

But be careful. “The most common mistake I see is attempting to add an additional RT or LT modifier when using modifier 50. Modifier 50 already indicates that the service was bilateral, so the use of these two additional modifiers would be incorrect,” advises Johnson. So, in our 19303 example, you would not document a bilateral mastectomy as 19303-LT, 19303-RT. But you would be correct in using either RT or LT if the surgeon removed only one of the patient’s breasts.

‘What Are the Payer’s Bilateral Guidelines?’

Even though CPT^® and Medicare both instruct you to use modifier 50 on one line of your claim when the modifier applies, some private payers do not follow these guidelines.

Consequently, you should check with your payers, as some may want you to report codes with bilateral modifiers on two lines with modifier 50 on the second line. Others may prefer two lines with the RT modifier on one line and the LT modifier on the other when appropriate.

Payer alert 3: Palmetto GBA, the Medicare Administrative Contractor (MAC) for Jurisdictions J and M, requires you to “submit the surgery or procedure on a single detail line with CPT^® modifier 50 and a quantity of 2,” or “on 2 detail lines, one with HCPCS modifier RT and one with HCPCS modifier LT” for any claims involving services with a bilateral surgery indicator of 3 (i.e. for radiological procedures. See www. palmettogba.com/palmetto/jmb.nsf/DIDC/7RDS2E5083~Specia lties~Surgery).