Right and Left not Right for Bilateral Surgical Procedures

on Monday, 07 July 2014. All News Items | Coding | Billing

Medicare MUEs and Correct Bilateral Billing

Have you ever seen the guy spinning numerous plates at once at the top of poles? This used to be a regular segment on the Ed Sullivan Show many years ago. Sometimes keeping up with all the different payer regulations is like spinning plates. For example, there are numerous ways to report bilateral procedures, but Medicare only wants it one way. Reporting it wrong will end up in a denial for certain procedures. Coders’ heads are spinning like those plates.

Medicare has published MLN Matters Article SE1422 to address improper Medicare billing of bilateral surgical procedures and date of service Medically Unlikely Edits (MUEs). As a reminder, per Medicare’s MUE webpage an MUE for a HCPCS/CPT code is the maximum units of service that a provider would report under most circumstances for a single patient on a single day of service.  Medicare FAQ 2277 explains that line-item MUEs are adjudicated separately against the MUE value for the procedure code on thatline. The appropriate use of CPT modifiers (such as -76, -77, -59, or anatomic modifiers) to report the same code on separate lines of a claim will enable a provider to report medically reasonable and necessary units of service in excess of an MUE value. 

Medicare, with back-up from the Office of Inspector General, is convinced that providers are inappropriately by-passing line item MUEs by reporting multiple line items. To address this concern, CMS is converting most MUEs into per day edits. That means that all lines of a CPT code will be denied if the units for that CPT code exceed the MUE limit for the day of service. In this case, reporting CPT codes on separate lines, with or without modifiers, will not by-pass the edits.

CMS is also adding MUE Adjudicator Indicators (MAIs) to indicate the type of MUE and its basis.

  • An MAI of 3 indicates an MUE based on clinical information such as billing patterns or prescribing information. Exceptions to the MUE limits can occur but would be rare, so Medicare considers items exceeding MUE limits when the MAI is 3 to be a billing error. Providers can appeal denials for MUEs with an MAI of 3 if they have verified that the units are correct, the service is medically necessary, and they have correctly interpreted all coding instructions.
  • An MAI of 2 indicates an MUE based on regulation or subregulatory instruction (“policy”), including the instruction that is inherent in the code descriptor or its applicable anatomy. MUE denials where the MAI is 2 will not be overturned on appeal.
  • If a provider receives an MUE denial and determines that the units originally billed were incorrect due to a clerical error, they can request a reopening instead of having to go through the appeals process. They can then submit a corrected claim with the correct number of units.

There is now a revised July 1, 2014 update on the MUE webpage that identifies the published MUE edits with an MAI value of 1 (line edit), 2 (date of service edit: policy) or 3 (date of service edit: clinical).

These per day MUEs will create a problem with bilateral codes for surgical procedures if they are not billed according to Medicare instructions. Medicare instructs in the Medicare Claims Processing Manual and the National Correct Coding Initiative Manual that bilateral surgical procedures (if bilateral is not included in the code description) should be reported using a single unit of service and the -50 modifier. If these procedures are incorrectly reported on two lines with RT and LT modifiers or on one line with units of 2, they may exceed the MUE if the per day MUE limit is one. A date of service MUE of one is fairly common for bilateral surgical procedures. The article only discusses bilateral surgical procedures; it does not address the correct reporting of bilateral radiology procedures.

Through our 835 claims analysis (HIQUP reports), MMP has identified denials of services that appear to be the result of inappropriate reporting of bilateral surgical procedures with RT and LT instead of the -50 modifier. For example, such CPT codes as 30140, 49505, 64483, and 67904 submitted with RT/LT modifiers are being denied with Claim Adjustment Reason Code (CARC) 151 (information submitted does not support this many services).

Hospitals need to watch for these types of denials and educate coders and billers or adjust chargemasters to assure bilateral surgical procedures are being reported correctly. Hospitals will also need to be aware of the per day MUEs and their respective MAIs for other services that may be affected. Something else to watch for and another acronym to remember.


Article by Debbie Rubio

Debbie Rubio, BS, MT (ASCP), is the Manager of Regulatory Affairs and Compliance at Medical Management Plus, Inc. Debbie has over twenty-seven years of experience in healthcare including nine years as the Clinical Compliance Coordinator at a large multi-facility health system. In her current position, Debbie monitors, interprets and communicates current and upcoming regulatory and compliance issues as they relate to specific entities concerning Medicare and other payers. You may contact Debbie at This email address is being protected from spambots. You need JavaScript enabled to view it. .


This material was compiled to share information. MMP, Inc. is not offering legal advice. Every reasonable effort has been taken to ensure the information is accurate and useful.

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