If you ignore the medically unlikely edits, you're asking for a claim rejection. If you're receiving denials from Medicare, one possibility is that you're running up against medically unlikely edits (MUEs). The edits, which are designed to prevent overpayments caused by gross billing errors, usually a result of clerical or billing systems' mistakes, often confuse even veteran coders. Ensure you're not letting MUEs wreak havoc on your practice's coding and reimbursement by uncovering the truth about four aspects of these edits. Myth 1: MUE Edits Don't Affect Your Practice Some practices feel that they don't need to worry about MUEs. Reality: "They limit the frequency a CPT code can be used," says Chandra L. Hines, business office manager at a practice in Raleigh, N.C. "We need to become aware of the denials and not let every denial go because the insurance company said it was an MUE. We should all be aware of MUEs as they occur, and we cannot always control whether or not we will receive payment." The MUE list includes specific CPT or HCPCS codes, followed by the number of units that CMS will pay. CMS developed the MUEs to reduce paid claims error rates in the Medicare Program, says Jillian Harrington, MHA, CPC, CPC-P, CPC-I, CCS-P, president of ComplyCode in Binghamton, N.Y. "The first edits were implemented in January 2007, although the edits themselves became public in October 2008," she adds. Some MUEs deal with anatomical impossibilities while others edit automatically the number of units of service you can bill for a service in any 24-hour period. Still others limit codes according to CMS policy. For example, segmental Doppler waveform analysis of both the lower and upper limbs (93923) has a bilateral indicator of "2," so you should not bill two or more units of this code. Additional edits focus on the nature of the equipment for testing, the study or procedure, or pathology specimen. Anatomical example: Unit of service example: Note: You can find the published edits on the CMS Web site. You can find a link to the MUEs and the MUE FAQs at www.cms.hhs.gov/NationalCorrectCodInitEd/08_MUE. asp. Myth 2: You Can Bill the Patient to Overcome MUE Limits Some practices believe that by having the patient sign an advance beneficiary notice (ABN) you can pass on the cost of procedures you know will be denied due to MUEs. Reality: CMS makes this rule very clear in its FAQs (http://questions.cms.hhs.gov), stating: "A provider/supplier may not issue an ABN for units of service in excess of an MUE. Furthermore, if services are denied based on an MUE, an ABN cannot be used to shift liability and bill the beneficiary for the denied services. It is a provider/supplier liability." Myth 3: You Can Never Override an MUE Don't think that even if your physician performs a legitimate, medically necessary procedure that violates MUE edits, you can't override the edits. Reality: How it works: A CMS FAQ states that "since each line of a claim is adjudicated separately against the MUE value for the code on that line, the appropriate use of Current Procedural Terminology (CPT) modifiers to report the same code on separate lines of a claim will enable a provider/supplier to report medically reasonable and necessary units of service in excess of an MUE value." CMS notes that modifiers 76 (Repeat procedure by same physician) and 77 (Repeat procedure by another physician) are among your options, as are the anatomical modifiers, such as RT (Right side). You may also use modifier 59 (Distinct procedural service), but Harrington cautions you to use this only if no other modifier is appropriate. You also may need to supply documentation showing medical necessity for the additional units. Myth 4: You Can't Appeal an MUE Denial If your practice receives a denial based on an MUE, you may think that you cannot appeal that denial. Reality: According to Harrington, you should follow three steps during the appeals process: Step 1: Step 2: Step 3: Tip: