Understanding Medically Unlikely Edits

Understanding Medically Unlikely Edits

Last week, CMS finally made public a number of Medically Unlikely Edits (MUEs) assigned to a series of CPT allergy codes. MUEs are claims edits used to limit the number of tests or treatments you can provide to a Medicare patient on a single date of service or on a single line of the claim form. Medicare implemented this program on Jan. 1, 2007 and you have been asking for guidance ever since! We’re here to help you fully understand the limits – because they are not going away.

Medicare was reluctant to release information on the allergy MUEs because they were afraid the maximum numbers would quickly become the base. Although the Advocacy Council argued against this line of thinking – because we do not believe you would knowingly bill for more doses or treatments than were medically necessary – until now our efforts were unsuccessful.

Below is a spreadsheet showing the MUE’s for all of the allergy codes. Note that each MUE has a “Medicare Adjudication Indicator” (MAI). This indicates whether the MUE is a line edit or a date of service edit. If it is a line edit, the MUE will be applied on a line basis. This may allow billing in excess of the MUE by using more than one line of the claim form. The date of service edits apply to all services provided on a given date. Eventually, CMS plans to convert all line edits to date of service edits (which does not allow billing on two different lines).

Medicare MUEs
Code MUE MUE Adjudication Indicator
95004 80 1 Line Edit
95012 2 3 Date of Service Edit: Clinical
95017 27 1 Line Edit
95018 19 3 Date of Service Edit: Clinical
95024 40 1 Line Edit
95027 90 1 Line Edit
95028 30 1 Line Edit
95044 80 1 Line Edit
95144 30 3 Date of Service Edit: Clinical
95145 10 3 Date of Service Edit: Clinical
95146 10 3 Date of Service Edit: Clinical
95147 10 3 Date of Service Edit: Clinical
95148 10 3 Date of Service Edit: Clinical
95149 10 3 Date of Service Edit: Clinical
95165 30 3 Date of Service Edit: Clinical
95170 10 3 Date of Service Edit: Clinical
95180 6 3 Date of Service Edit: Clinical


Note that the MUE for 95144 and 95165 is 30. This is based on the Medicare definition of dose which is one cc. Under this MUE you can bill for up to 30 ccs of extract on a given date even though that may be more than 30 clinical doses. This is a Medicare definition only and does not limit the number of doses that other payers may pay.  If you become aware that other payers are attempting to limit the number of doses to 30 based on Medicare policy, please let the Advocacy Council know.

The number three (3) in front of the adjudicator indicator means that the contractor can bypass the MUE, based on clinical necessity. Following is an excerpt from the national correct coding initiative (NCCI) policy manual which reads:

  • “If contractors have evidence (e.g. medical review) that UOS (unit of service) in excess of the MUE value were actually provided, were correctly coded and were medically necessary, the contractor may bypass the MUE for a HCPCS code with an MAI (MUE adjudication indicator) of “3” during claim processing, reopening or redetermination, or in response to effectuation instructions from a reconsideration or higher level appeal.”

It is also important to understand that your individual Medicare Administrative Contractor (MACs) can implement medical necessity limits that may be more restrictive than MUE’s. The manual states:

  • “Since MUE’s are coding edits rather than medical necessity edits, claims processing contractors may have units of service edits that are more restrictive than MUE’s. 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.”

If you have any questions regarding MUEs, email them to the Advocacy Council of ACAAI.