MAC Clarifies Modifier 50 Appropriate Use

Modifier 50 Appropriate UseNovitas Solutions recently issued a Modifier 50 Fact Sheet, reminding medical coders of the proper use for this CPT payment modifier. The Medicare Administrative Contractor (MAC) for jurisdictions H and L warns that, effective for Part B claims received on and after Aug. 16, 2019, services will be rejected as unprocessable when modifier 50 Bilateral procedure is used inappropriately.

When is the right time to append modifier 50?

Macs Have The Facts

All MACs have the same general policy for this modifier, and all are on the lookout for improper modifier use. The biggest problem, Novitas reports, is the units of service (UOS).

Appropriate Use:
  • Report one line with modifier 50 using one UOS.
  • If more than one bilateral procedure was performed, the UOS should be adjusted to reflect the number of bilateral procedures performed.

Novitas provides the following example:

Procedure code 19303 Mastectomy, simple, complete is performed bilaterally. Correct coding, as of July 1, 2019, is CPT 19303-50.

Do not use HCPCS anatomical modifiers LT Left and RT Right when a procedure is performed bilaterally. These modifiers are for when a bilateral procedure is performed only on one side.

One Tool Holds All The Answers

To know for sure if modifier 50 is appropriate, check the code’s bilateral indicator in the Medicare Physician Fee Schedule (PFS) lookup tool. The rules are:

  • Do not append modifier 50 to a code with a bilateral surgery indicator of 0, 2 or 9.
  • Modifier 50 may be appropriate if the bilateral indicator is 1 or 3.

Also check the code’s medically unlikely edit (MUE) adjudication indicator. When reporting bilateral surgical procedures that have a MUE adjudication indicator 2 or 3, append modifier 50 and one unit of service. According to National Government Services, MAC for jurisdictions 6 and K, “One common coding error made while reporting MUEs is the use of modifier 50 for bilateral procedures along with a UOS of two (2).”

Also read the code description. If the description indicates the procedure is bilateral, do not append modifier 50.

Different Rules For ASCS

According to Medicare billing guidelines, modifier 50 is not recognized for payment purposes under the Ambulatory Surgical Center Prospective Payment System. Report bilateral procedures as a single unit on two separate lines or a single unit with two units. The 50 percent multiple procedure reduction may apply to procedures performed on the same day.

Don’t Report Modifiers 50 And 78 Together

CGS, MAC for jurisdiction 15, states on its website:

If a (subsequent) bilateral procedure requires a return to the operating room after the initial surgery, and the bilateral indicator in the MPFSDB is 1 or 2, do not submit CPT modifier 50. CPT modifiers 50 and 78 cannot be submitted for the same service. Instead, submit the surgery procedure code with CPT modifier 78 and HCPCS modifier RT on one detail line, and submit the same surgery procedure code with CPT modifier 78 and HCPCS modifier LT on a separate detail line.

For More Information: https://www.aapc.com/blog/47731-mac-clarifies-modifier-50-appropriate-use/