Coding
Modifier -25 Use in Dermatology
Modifier -25 frequently is integral to the description of patient visits in dermatology. Dermatologists use modifier -25 more than physicians of...
Medically Unlikely Edits (MUEs) are benchmarks recognized by the Centers for Medicare & Medicaid Services (CMS) that are designed to prevent incorrect or excessive coding. Specifically, an MUE is an edit that tests medical claims for services billed in excess of the maximum number of units of service permitted for a single beneficiary on the same date of service from the same provider (eg, multiples of the same Healthcare Common Procedure Coding System [HCPCS] code listed on different claim lines).1
The MUE System
If the number of units of service billed by the same physician for the same patient on the same day exceeds the maximum number permitted by the CMS, the Medicare Administrative Contractor (MAC) will deny the code or return the claim to the provider for correction (return to provider [RTP]). Units of service billed in excess of the MUE will not be paid, but other services billed on the same claim form may still be paid. In the case of an MUE-associated RTP, the provider should resubmit a corrected claim, not an appeal; however, an appeal is possible in the case of an MUE-associated denial. An MUE-associated denial is a coding denial, not a medical necessity denial; therefore, the provider cannot use an Advance Beneficiary Notice to transfer liability for claim payment to the patient.
MUE Adjudication Indicators
In 2013, the CMS modified the MUE process to include 3 different MUE adjudication indicators (MAIs) with a value of 1, 2, or 3 so that some MUE values would be date of service edits rather than claim line edits.2 Medically Unlikely Edits for HCPCS codes with an MAI of 1 are identical to the prior claim line edits. If a provider needs to report excess units of service with an MAI of 1, appropriate modifiers should be used to report them on separate lines of a claim. Current Procedural Terminology (CPT) modifiers such as -76 (repeat procedure or service by the same physician) and -91 (repeat clinical diagnostic laboratory test) as well as anatomic modifiers (eg, RT, LT, F1, F2) may be used, with modifier -59 (distinct procedural service) used only if no other modifier suffices. An example of an MUE with an MAI of 1 is CPT code 17264 (destruction, malignant lesion [eg, laser surgery, electrosurgery, cryosurgery, chemosurgery, surgical curettement], trunk, arms or legs; lesion diameter 3.1–4.0 cm), for which the MUE threshold is 3, meaning no more than 3 destructions can be submitted per claim line without triggering an edit-based rejection or RTP.
An MAI of 2 denotes absolute date of service edits, or so-called “per day edits based on policy.” Such edits are in place because units of service billed in excess of the MUE value on the same date of service are considered to be impossible by the CMS based on regulatory guidance or anatomic considerations.2 For instance, although the same physician may destroy multiple actinic keratoses in a single patient on the same date of service, it would not be possible to code more than one unit of service as CPT code 17000, which specifically and exclusively refers to the first lesion destroyed. Similarly, CPT code 13101 (repair, complex, trunk; lesion diameter 2.6–7.5 cm) could only be reported once that day, as all complex repairs at that anatomic site must be summed and smaller or larger totals would be reported with another code.
Anatomic limitations are sometimes obvious and do not require specific coding rules. For example, only 1 gallbladder can be removed per patient. Although Qualified Independent Contractors and Administrative Law Judges are not bound by MAIs, they do give particular deference to an MAI of 2 given its definitive nature.2 Because ambulatory surgical center providers (Medicare specialty code 49) cannot report modifier -50 for bilateral procedures, the MUE value used for editing is doubled for HCPCS codes with an MAI of 2 or 3 if the bilateral surgery indicator for the HCPCS code is 1.3
An MAI of 3 describes less strict date of service edits, so-called “per day edits based on clinical benchmarks.”2 Similar to MAIs of 1, MUEs for MAIs of 3 are based on medically likely daily frequencies of services provided in most settings. To determine if an MUE with an MAI of 3 has been reached, the MAC sums the units of service billed on all claim lines of the current claim as well as all prior paid claims for the same patient billed by the same provider on the same date of service. If the total units of service obtained in this manner exceeds the MUE value, then all claim lines with the relevant code for the current claim will be denied, but prior paid claims will not be adjusted. Denials based on MUEs for codes with an MAI of 3 can be appealed to the local MAC. Successful appeals require documentation that the units of service in excess of the MUE value were actually delivered and demonstration of medical necessity.2 An example of a CPT code with an MAI of 3 is 40490 (biopsy of lip) for which the MUE value is 3.