Dermatology World • January 2022 • Coding Consult

Academy coding staff address important coding topics each month in DermWorld Coding Consult. To read more Derm Coding Consult articles, visit www.aad.org/dcc.

CMS has released its third and fourth quarterly updates to the National Correct Coding Initiative (NCCI) procedure-to-procedure (PTP) edits. Version 27.2 and version 27.3 went into effect on July 1, and Oct. 1, 2021, respectively.

The NCCI PTP code pair edits were designed to prevent improper payments when incorrect code combinations are reported for Medicare Part B covered services by physicians and non-physician clinicians (NPCs).

The NCCI table (www.cms.gov/Medicare/Coding/NationalCorrectCodInit-Ed/NCCI-Coding-Edits) lists Healthcare Common Procedure Coding System code and Current Procedural Terminology (HCPCS/CPT) code combinations that are mutually exclusive from one another. When these codes are billed together on the same day by the same physician or NPC for the same patient, one of the services may be bundled into the primary procedure resulting in denial of the claim line. To avoid bundling of claim lines, one of the codes must be appended with a modifier (www.aad.org/member/practice/coding/modifiers) to indicate that the service was performed either:

Each edit has a column one and column two HCPCS/CPT code. If a provider reports the two codes of an edit pair, the column two code is denied, and the column one code is eligible for payment. However, if it is clinically appropriate to use an NCCI PTPassociated modifier, both the column one and column two codes are eligible for payment.

Although there are currently not many changes to dermatology-related NCCI edits, it is important for dermatology practices to conduct periodic reviews of the NCCI table to ensure that where applicable, the claim line is appended with the appropriate modifier(s).

In its continued effort to lower the Medicare Fee-For-Service (MFFS) paid claims error rate, CMS has also established units of service edits known as Medically Unlikely Edits (MUEs). An MUE for a HCPCS/CPT code is the maximum unit of service that a dermatologist or NPC would report under most circumstances for a single beneficiary on a single date of service.

Not all HCPCS/CPT codes have an MUE; however, Medicare Administrative Contractors (MACs) test codes with established MUEs against these edits during claim adjudication. Codes reported with MUEs more than the established maximum units are denied.

MUE values for each HCPCS/CPT code are based on and described by an MUE Adjudication Indicator (MAI). Every dermatology practice must conduct a periodic review of the NCCI PTP and MUE indicators to understand the rationale for MUE claim denial(s) so that claim appeals based on NCCI or MUE edits can be successfully addressed.

Certain billing circumstances may clinically require reporting the service in excess of the listed MUE. For example, CPT code 88342 - Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure has an MUE of 4 and an MAI of 3 – date of service - clinical edit. When more than four units of this service are performed by the same provider on the same date of service to the same patient, the excess units can be appealed with medical records to justify the medical necessity.

Claim denials based on MUE MAI are sometimes appealable — depending on the MUE rationale. Below are the MUE indicators and their interpretation as well as actions you can take to appeal denied claims once they meet appeal criteria.

For more coding help on the appropriate use of modifiers visit www.aad.org/coding.