Q&A: Finding the correct MS-DRG

Q: I’m new to coding and am having trouble understanding how to find the correct MS-DRG for a patient. Could you walk me through the process?

A: Something that can be very confusing to new inpatient coders is that the DRG Expert is not a code book. This means that it does not contain all the codes that a code book would. Because the DRG Expert does not contain all the codes you need to know, when you can’t find a diagnosis or procedure using the Alphabetic Index, what would you do?

Let’s take a look at the process for coding a record. The first step would be to look at the documentation and identify the principal diagnosis for the encounter you’re reviewing. Then find any procedures providers performed during the encounter that are considered reimbursable, and lastly, any conditions that CMS has identified as CCs or MCCs.

Once you have identified the principal diagnosis, it is necessary to identify its major diagnostic category (MDC) by identifying which MS-DRG it would be assigned to.

How is this accomplished? You have to be able to look it up either alphabetically or numerically in one of the indexes provided in the DRG Expert. How do you decide which path to go down? Sometimes you have no choice. Some conditions are not found in the Alphabetic Index no matter what terminology you use.

Let’s take a look at a condition that is often the cause of an inpatient admission and would not be found alphabetically in the DRG Expert.

Most people are surprised to find that the diagnosis of “sepsis” is not listed alphabetically and would require you to know the code to look it up and identify the MS-DRG and ultimately the right MDC. Sepsis from an unspecified organism is coded to ICD-10-CM code A41.9 and once you know that, you can use the numeric index to find out the MS-DRG and MDC.

You have a couple of options when it comes to identifying the code. You could look it up in the ICD-10-CM/PCS code book, you could contact others in the coding department and ask for help, or look it up using a search engine or app.

After you find the appropriate MS-DRG and the MDC the code belongs to, you need to see if the patient has had a reimbursable procedure, which could move you from a medical DRG to a surgical DRG. With the addition of a CC/MCC, the final MS-DRG assignment would be identified.

Editor’s Note: Sharme Brodie, RN, CCDS, CDI education specialist and CDI Boot Camp instructor for HCPro in Middleton, Massachusetts, answered this question. The original version of this Q&A appeared in CDI Strategies. For information, contact her at sbrodie@hcpro.com. 

This answer was provided based on limited information. Be sure to review all documentation specific to your own individual scenario before determining appropriate code assignment.

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