Knowledge Base Article

National Correct Coding Initiative (NCCI) edits have been around since 1996 and Medically Unlikely Edits (MUEs) since 2007, but do you know what they are, why they were developed, how to read the tables, and when and how to appropriately by-pass these Medicare edits? And more importantly, do you realize these edits impact your reimbursement and compliance risk?

Both sets of edits were developed by CMS to reduce inappropriate payments for Part B claims. NCCI edits are based on coding guidelines, conventions and practices and are designed to prevent improper coding and payment. CCI edits originally applied only to physician billing, but there are now tables for physicians and a subset of edits for hospital providers. There are separate MUE tables for practitioner services, facility outpatient services, and DME supplier services.

The MUE table is straightforward with a column for the CPT/HCPCS code and a column for the MUE limit. An MUE for a HCPCS/CPT code is the maximum units of service that a provider would report under most circumstances for a single beneficiary on a single date of service. Although CMS publishes most MUE values on its website, other MUE values are confidential and are for CMS and CMS Contractors' use only.  

The NCCI table includes code pairs that generally should not be reported together for a number of reasons as explained in the Coding Policy Manual. If both codes of a code-pair edit are reported together for the same date of service by the same provider without an NCCI-modifier, the column 1 code will be paid and the column 2 code will be denied. In addition to the code pair, effective date, and deletion date if applicable, the table includes a modifier indicator that indicates if a modifier is allowed to by-pass the CCI edit when appropriate. An indicator of “1” means a modifier is allowed, “0” means a modifier is not allowed to by-pass the edit and “9” is not applicable (canceled edits).

NCCI edits and MUEs are updated quarterly. The latest versions of the edits are available on Medicare’s NCCI webpage. Also, Medicare publishes the revisions for the quarter for both CCI edits and MUEs.   The MUE updates include additions, deletions, and revisions to the MUE quantity. The CCI edits include additions, deletions and revisions to the modifier indicator.

Tips on Dealing with the Edits

• First and foremost, modifiers should only be used to by-pass the edits when it is appropriate to do so.
• Modifiers are allowed for CCI edits when separate procedures are performed, such as a separate encounter, separate anatomic sites, or separate specimens. Modifiers are appended to the column 2 code of a code pair.
• For MUEs a modifier would be appropriate when the quantity performed exceeds the MUE limit. Separate line items must be reported on the claim so that no single line item quantity exceeds the MUE limit. Modifiers are added to the second and additional line items.
• There are “date of service” MUEs that cannot be bypassed with a modifier. All units of a code with a date of service MUE are denied if the quantity for that date exceeds the MUE limit.
• Acceptable modifiers to by-pass edits include anatomic modifiers: E1-E4, FA, F1-F9, TA, T1-T9, LT, RT, LC, LD, RC, LM, RI; global surgery modifiers: 24, 25, 57, 58, 78, 79; and other modifiers: 27, 59, 91.
• Refer to the NCCI Policy Manual for a better understanding of the edits and their reasoning. There is a general chapter and then chapters for each CPT/HCPCS code group (such as codes 80000-89999). This manual contains valuable information about correct coding and the edit principals.
• Coders generally apply modifiers for surgical codes when appropriate, but ancillary code pairs may not be identified until processing through facility billing systems. Input from the ancillary department is often necessary to know if it is appropriate to append a modifier to by-pass the code-pair edit. Hospital billers should have a system in place and contact people in the ancillary areas to assist with CCI edits.

NCCI edits and MUEs apply to Medicare and Medicaid claims. Some other payers may also expect providers to follow the edits. MMP recommends you check with payers to determine if they follow these edits or perhaps have some “coding” edits of their own.