Coding Corner: How to appropriately apply modifiers LT, RT and 50

March 06, 2019
Area(s) of Interest: Practice Management Payor Issues and Reimbursement 

CPR’s “Coding Corner” focuses on coding, compliance, and documentation issues relating specifically to physician billing. This month’s tip comes from G. John Verhovshek, the managing editor for AAPC, a training and credentialing association for the business side of health care.

Confusion about when to append CPT® modifier 50 Bilateral procedure, versus HCPCS Level II modifiers LT Left side and RT Right side is common. Guidelines for modifier 50 are well established, but this is less true for the HCPCS modifiers. Ultimately, proper modifier application depends on the particulars of the claim and your payor’s preference.

One structure, two sides, calls for modifier 50

Modifier 50 may apply when two procedures, reported using the same CPT® code, are performed on both sides of a single, symmetrical structure or organ, such as the spine, the skull or the nose. For example, spinal laminotomy (63020-63044) may occur on either side of the spine, or on both sides of the spine at the same level(s).

In other cases, modifier 50 may apply when procedures described by the same CPT® code are performed on “paired” structures, such as eyes, arms, legs, breasts or kidneys. For example, removal of malignant breast tissue may be performed on one breast (unilaterally), or on both breasts (bilaterally).

You may append modifier 50 only to those codes not already defined as bilateral by a specific CPT® code. For example, CPT® designates 22510 Percutaneous vertebroplasty (bone biopsy included when performed), 1 vertebral body, unilateral or bilateral injection, inclusive of all imaging guidance; cervicothoracic as either a unilateral or bilateral procedure; therefore, this code may not be reported with modifier 50.

Most coding and billing software will identify those codes to which modifier 50 may be appended, but you can find the same information in the Medicare Physician Fee Schedule (MPFS) Relative Value File, which you can download for free on the Centers for Medicare & Medicaid Services website. Within the MPFS, the column labeled “BILAT SURG” column lists various modifier indicators. You may append modifier 50 only to those codes with a “1” modifier indicator

Modifier 50 affects payment

For Medicare and many commercial payors, proper application of modifier 50 increases reimbursement to 150 percent of the allowable fee schedule payment for the code to which the modifier is appended.

For example, Medicare values excision of lesion as described by 11600 Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter 0.5 cm or less at approximately $200. The MPFS Relative Value File shows a 1 modifier indicator in the BILAT SURG column for this code; therefore, modifier 50 may be appended to describe a bilateral procedure (for example, for excision of a lesion on the left arm, and another excision of lesion of the same type on the right arm). When reported with modifier 50, the value of 11600 increases to approximately $300.

Medicare carriers for Part B services have specified that you should report modifier 50 claims as a single line item (e.g., 11600-50 x 1, in the example, above). Some payors may require you to report two line items, with modifier 50 appended to the second code unit (e.g., 11600, 11600-50). Check with your payor for its preference.  

LT/RT paint a more detailed picture

Modifiers LT and RT provide supplemental information for procedures performed on paired structures such as the eyes, lungs, arms, breasts, knees, etc. These modifiers don’t directly affect payment, but provide vital information to identify the location of a service.

As an example, a surgeon may perform an excision (19120) from the left breast and a needle core biopsy (19100 Biopsy of breast; percutaneous, needle core, not using imaging guidance (separate procedure)) on the right breast. Excision includes biopsy at the same location (unless further excision was prompted by biopsy results). But when the procedures occur on opposing breasts, you may report them separately, in this case using 19120-LT and 19100-RT. Some payors may require additionally that you append modifier 59 Distinct procedural service to 19100.

Modifiers LT and RT also may be used to describe rare cases when a provider performs unilaterally a procedure that CPT® defines as bilateral. For example, 58953 Bilateral salpingo-oophorectomy with omentectomy, total abdominal hysterectomy and radical dissection for debulking is, by definition, a bilateral procedure. If the procedure is performed on the right side only, appropriate reporting is 58953 with modifier 52 Reduced procedure, along with modifier RT to specify location.

Finally, modifiers LT and RT may be used to provide location-specific information for those services defined either as unilateral or bilateral, such as ablation of soft tissue codes 30801 Ablation, soft tissue of inferior turbinates, unilateral or bilateral, any method (eg, electrocautery, radiofrequency ablation, or tissue volume reduction); superficial. If this procedure were performed unilaterally on the left side, you would report 30801 to improve claims specificity.

Save the Date for AAPC’s HEALTHCON 2019, April 28 to May 1

AAPC, a training and credentialing association for the business side of health care, is hosting its 26th annual HEALTHCON on April 28 to May 1, 2019, in Las Vegas, Nevada. The conference is geared toward all levels of medical practice leadership and will offer attendees a multitude of tools and resources to help guide them to success, including:

  • Over 120 educational sessions featuring the industry’s hottest topics, including a presentation by Karen DeSalvo, M.D., President Obama’s Acting Assistant Secretary for Health.
  • 3,000 health care professionals to network with.
  • More than 75 exhibitors for a chance to learn about the latest products and services in the industry.

For more information or to register, click here.

AAPC has long been the California Medical Association’s (CMA) partner in billing and coding education, providing CMA’s monthly “Coding Corner” column and offering key education for the ICD-10 transition.


Was this article helpful?    
Download the New CMADocs app!

Download the new CMADocs app!

CMA's new mobile app lets you connect with your colleagues and engage with CMA content!  Download the "CMADocs" app today from the Apple or Google Play app stores for daily news updates, events calendar, resource library and more.

Latest News

Load More