Medical Unlikely Edits Implemented for Some HCPCS and CPT Codes

Table of Contents

• Medical Unlikely Edits Implemented for Some HCPCS and CPT Codes
• Looking Up MUEs
• Accessing MUE Tables
• Common Questions

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Medical Unlikely Edits Implemented for Some HCPCS and CPT Codes

National Government Services has seen an increase in the number of claims editing as MUEs. CMS developed MUEs in 2007 to reduce the paid claims error rate for Part B claims. An MUE for a HCPCS/CPT code is the maximum UOS that a provider would report under most circumstances for one beneficiary on one DOS. All HCPCS/CPT codes do not have an MUE.

The Medicare NCCI, also known as CCI, was implemented to promote national correct coding methodologies and to control improper coding leading to inappropriate payment. NCCI code pair edits are automated prepayment edits that prevent improper payment when certain codes are submitted together for Part B-covered services.

CMS is converting some claim line MUEs to DOS MUEs. The total UOS from all claim lines for a HCPCS/CPT code with the same DOS will be summed and compared to the MUE value.

Claims denied based on DOS MUEs may be appealed using similar processes to claim line MUE denials. DOS MUEs are based on criteria including but not limited to, anatomic considerations, CPT code descriptors or instructions, and nature of equipment or service. CMS does not publish which codes have DOS MUEs. Since all UOS for a HCPCS/CPT code on all claim lines with the same DOS are summed, reporting additional UOS on separate claim lines with a HCPCS/CPT modifier will not result in payment of UOS in excess of the MUE value improper payment when certain codes are submitted together for Part B-covered services.

Accurate coding and reporting of services are critical aspects of proper billing. Services denied based on NCCI code pair edits or MUEs may not be billed to Medicare beneficiaries; a provider cannot utilize an ABN to seek payment from a Medicare beneficiary.

One common coding error made while reporting MUEs is the use of modifier 50 for bilateral procedures along with a UOS of two (2). CMS requires providers (except ASC) to report a bilateral surgical procedure on a single claim line with modifier 50 and only one (1) UOS. Although ASCs cannot use modifier 50, they should either be billing two UOS on one detail or they should be billing on separate details using RT/LT modifiers.

• Modifier 50 is used to report bilateral procedures that are performed at the same operative session as a single line item. Do not use modifiers RT and LT when modifier 50 applies. Do not submit two line items to report a bilateral procedure using modifier 50.
• Modifier 50 applies to any bilateral procedure performed on both sides at the same operative session. The bilateral modifier 50 is restricted to operative sessions only.
• Modifier 50 may not be used to report surgical procedures identified by their terminology as “bilateral,” or surgical procedures identified by their terminology as “unilateral or bilateral”.
• The unit entry to use when modifier 50 is reported is one.

As a reminder, providers should use the anatomic modifiers, (e.g., RT, LT, FA, F1-F9, TA, T1-T9, E1-E4) and report procedures with differing modifiers on individual claim lines when appropriate.

MUE is utilized to adjudicate claims at A/B MACs and DME MACs.

For MUEs that are adjudicated as claim line edits, each line of a claim is adjudicated separately against the MUE value for the code on that line. The appropriate use of HCPCS/CPT modifiers to report the same code on separate lines of a claim will enable a provider/supplier to report medically reasonable and necessary UOS in excess of a MUE value. CPT modifiers such as 76 (repeat procedure by same physician), 77 (repeat procedure by another physician), anatomic modifiers, (e.g., RT, LT, F1, F2), 91 (repeat clinical diagnostic laboratory test), and modifier 59 (distinct procedural service) will accomplish this purpose. Modifier 59 should be utilized only if no other modifier describes the service. For MUEs that are adjudicated as DOS edits, UOS in excess of the MUE value may be paid during the appeal process.

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Looking Up MUEs

MUEs are developed based on HCPCS/CPT code descriptors, CPT coding instructions, anatomic considerations, established CMS policies, nature of service/procedure, nature of analyte, nature of equipment, prescribing information, and clinical judgment.

Note: Most MUEs are visible to providers on the Web site; however, some MUEs are considered confidential by CMS and are not released.

Claims processing contractors may have UOS edits that are more restrictive than MUEs. In such cases, the more restrictive claims processing contractor edit would be applied to the claim. Similarly, if the MUE is more restrictive than a claims processing contractor edit, the more restrictive MUE would apply.

MUE values are not utilization guidelines and do not represent UOS that may be reported without concern about medical review. Providers should continue to only report services that are medically reasonable and necessary. Providers may be subject to medical review of their claims even if they report UOS less than or equal to the MUE value for a code.

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Accessing MUE Tables

MUE tables are available on the CMS website at Medicare NCCI Medically Unlikely Edits (MUEs).

• Click on the above link and scroll to the bottom of the web page
• Under the Related Downloads section, click on the link for the table you want to review
• The MUE tables are in compressed zipped files. You must choose either “open” or “save” the file for future reference.
  • MUE tables are updated quarterly, saved tables must be replaced in order to have the most current information.

The tables can be viewed as either a plain text file or a Microsoft Excel spreadsheet.

• The first column displays the HCPCS/CPT Code with an MUE value.
• The second column displays the Services MUE Values showing the maximum UOS that a practitioner would report under most circumstances for a single beneficiary on a single DOS.

Unlike the code pair tables, the MUE tables do not have a column that addresses modifiers. View the MLN® Booklet: How to Use the Medicare National Correct Coding Initiative (NCCI) Tools for information about modifiers and MUEs.

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Common Questions

1. What is an MUE?
   
   Answer: An MUE is the maximum UOS that a provider would report under most circumstances for a single beneficiary on a single DOS. MUEs are applied to HCPCS and CPT codes however all HCPCS/CPT codes do not have an MUE. CMS developed MUEs in 1997 to reduce the paid claims error rate for Part B claims.
    
2. Where can I find what HCPCS/CPT codes have MUE values?
   
   Answer: CMS maintains a list of published MUEs on their website. Note: Not all HCPCS/CPT codes have an MUE value, and not all MUE values are published.
    
3. Where can I find the maximum allowable units for procedures codes?
   
   Answer: The published listing of the maximum allowable units for procedure codes to be performed/billed per day can be found by accessing the MUE spreadsheet on the CMS website. Note: Not all procedure codes have an MUE and not all procedures that do have MUEs are published.
    
4. Where can I find more information about MUEs?
   
   Answer: Medicare NCCI Medically Unlikely Edits (MUEs) web page offers additional information. 

Revised 8/6/2024