A question I commonly answer is whether it is okay to report more than 1 unit of a particular CPT code. This is a very valid question when you are looking at a report that describes multiple procedures that would be reported with the same CPT code. A great resource to help with these questions is the Maximum Unit Edits (MUEs) that are published by Medicare each quarter. While this resource is payer specific (meaning it is Medicare’s rules for how many units of a code they would consider appropriate and payable), many mainstream commercial payers like United Healthcare follow Medicare’s payment policies. So starting here can give you great insight on whether you have a good understanding of the code and the guidelines to appropriately use the code. If you find yourself routinely coding in excess of the MUE for a code, it is a signal to pause and review the guidelines and the code definition because it would be unlikely that coding in excess of the MUEs on a routine basis is correct.
You can find the Maximum Unit Edits for Medicare at the following link: CMS MUEs. These edits are updated every quarter so when you arrive at the website, scroll down to the “Downloads” box at the bottom of the page and click on the link for the latest edit file (at the time of publication of this article, this would be the Practitioner Services MUE Table – Effective -10-01-2020 when coding professional services for physicians and other qualified healthcare providers):
Once you click on the link, you will be offered an option to open or save the file. I would encourage you to save the file to your computer for easy access. Be sure to go back to the website and download a copy of the current edit file each quarter.
Once you have your file downloaded, you will want to get familiar with the format of the file and the information it can provide:
- Column A lists the CPT/HCPCS codes for any codes which have an MUE. If you don’t find a code listed in column A, it does not have an MUE. Not every code will have an MUE but codes that are routinely miscoded or overpaid will be listed.
- Column B lists the maximum number of units that would typically be paid for that code when reported by the same physician (or a physician in the same specialty and group) for the same patient on the same date of service.
- Column C lists the MUE Adjudication Indicator (MAI) which will explain the payer’s policy for that type of edit. There are three different MAIs that may be assigned to a code. I have included the definitions of each MAI below, but you can also find this information in the NCCI Policy Manual, Chapter 1, section V:
- 1 – Line item edit: This type of edit represents the maximum number of units of a code that may be paid on a single line on a claim. It may be possible to bypass this edit by reporting the same CPT on more than one line of the claim and adding appropriate modifiers such as 59 or 76. This type of MUE is more common with lab/pathology services than surgical services so we will focus more heavily on the remaining MAIs in this article.
- 2 – Date of service edit: This type of edit represents the maximum number of units of a code that may be reported by the same physician (or physicians in the same specialty and group) for the same patient on the same date of service. These edits are considered “binding” on providers and contractors processing claims based on anatomy or the definition of a code. In other words, you should not code in excess of the MUE for a code with this MAI indicator (to do so is considered a coding error per Medicare guidelines).
- 3 – Date of service edit: This type of edit represents the maximum number of units of a code that Medicare expects to be reported by the same physician (or physicians in the same specialty and group) for the same patient on the same date of service. This edit is similar to the MAI indicator of 2, but this type of MUE may be exceeded when documentation supports coding in excess of the MUEs for a particular CPT code(s). You will receive a denial initially and must submit documentation supporting the fact that exceeding the MUE for the code is appropriate since Medicare views reporting more units than that typically allowed to be the exception not the norm.
- Column D provides a rationale for why Medicare added an MUE for the code. There are many different rationales for MUEs, but to provide a couple examples, the edit may be based on anatomy (i.e., CPT 44970 for a laparoscopic appendectomy has an MUE of 1 unit based on anatomic considerations since each patient has only 1 appendix so we can code for the removal of that appendix only once). Other edits may be based on claims data and the average number of units reported by physicians in similar practices/specialties. The goal of this information is to help explain how Medicare arrived at the decision to limit the number of units for a particular code and help you better understand when reporting in excess of the MUE might be appropriate.
Let’s work through a couple of examples to see how the MUE tables can help you code with accuracy.
Example #1: Is it appropriate to code more than one unit for suture of the brachial plexus (CPT 64861)?
Answer Example #1: With the MUE file open on your computer, hit the Ctrl and F keys on your keyboard to bring up a search box. Type in 64861 and hit enter to search for the CPT code:
You should now see the search results below:
We can see that CPT 64861 has an MUE of 1 unit in column B and the MAI in column C is “2: Date of Service Edit” with a rationale of “CMS Policy” in Column D. This means that you may only report 1 unit of the code when submitting a claim to Medicare or a payer following their payment policies. With the MAI of 2: Date of Service, it would be considered a coding error to report more than 1 unit of the code.
Example #2: How many units of CPT 92920 (angioplasty single major coronary artery or branch) may be reported during the same encounter?
Answer Example #2: With the MUE file open, search for 92920 following the steps described above in example #1. You should now see the following search results:
We can see that CPT 92920 has an MUE of 3 units in column B and the MAI in column C is “3: Date of Service Edit” with a rationale of “Code Descriptor/CPT Instruction.” So we could report up to 3 units of 92920 during a single encounter without receiving a denial. We could also report more than 3 units in the rare case that documentation supported doing so. Before submitting the claim, though, we need to first consult the CPT code description and the CPT instructions for use of the code to make sure we are coding appropriately. To illustrate this, a CPT guideline that is critical for coding interventions like angioplasty in coronary arteries is that “Only one base code from this family may be reported for revascularization of a major coronary artery and its recognized branches.” The guidelines also define the major coronary arteries and their recognized branches: “Major coronary arteries: The major coronary arteries are the left main, left anterior descending, left circumflex, right, and ramus intermedius arteries. Coronary artery branches: Up to two coronary artery branches of the left anterior descending (diagonals), left circumflex (marginals), and right (posterior descending, posterolaterals) coronary arteries are recognized.” Considering all of these guidelines, you cannot code more than one base code like 92920 in a single major coronary artery with its associated branches which means it is only possible to report up to 5 base codes in any one case (based on the number of recognized major coronary arteries). The MUE of 3 is set for CPT 92920 because it is highly unlikely to report more than 3 angioplasties in these 5 recognized major coronary arteries/families during the same encounter. So while the MAI would allow you to code in excess of the 3 units, you should pause and carefully review guidelines and documentation to make sure you are doing so correctly before coding in excess of those 3 units.
I hope that helps to illustrate use of this invaluable tool to assist with accurate coding.
