Coding Influenza

It’s that time of year again, when the public is reminded to get their flu shots.  That makes it a good time to review the coding of influenza in this segment of “In the kNOW”.

Let’s start by looking at the ICD-10-PCS procedure for a flu shot.  Last year, a revision was made in table 3E0 that gave facilities the ability to track flu shots.  This code begins in the Administration Section of PCS.  So let’s look at how the rest of the ICD-10-PCS would be built.

Section    - Administration
Body System - Physiological Systems and Anatomical Regions
Root Operation - Introduction
Body System/Region - Subcutaneous tissue
Approach - Percutaneous
Substance - Serum, Toxoid and Vaccine
Qualifier - Influenza Vaccine

This provides organizations with a method of tracking flu shots administered in an inpatient setting.

Now, when we look at the ICD-10-CM coding of influenza there are a variety of codes that could be reported based on the type of influenza (A, B), if known, and the manifestations that the patient is exhibiting.  Manifestations can include pneumonia, myocarditis, otitis media, encephalopathy, gastrointestinal problems such as enteritis, or other respiratory conditions like laryngitis or pharyngitis. 

It is vital to note that Influenza A is NOT the same as Novel Influenza A (H1N1 or H5N1) which is swine or bird flu.  Influenza A would take you to category J10, while the Novel Influenza A to category J09.

Assignment of Influenza A (J10.1) as the principal diagnosis without any other manifestations will take you to MS-DRG 195 Simple Pneumonia and Pleurisy without MCC with a weight of 0.6868.  Should there be an MCC to code, the MS-DRG would shift to 193 with a weight of 1.3167.  Interestingly, if the Novel Influenza A (J09.X2) is coded, it will be housed in the same MS-DRG as Influenza A.   However, notice the difference if either type of influenza is accompanied with other manifestations which would lead to MS-DRG 866 Viral Illness without MCC with a relative weight of 0.8204, of if an MCC is present, lead to MS-DRG 865 with a weight of 1.3822.

There is also a difference in MS-DRG assignment for unidentified influenza cases coded as J11.1.  Those that do not have an MCC are assigned to MS-DRG 153 Otitis Media and URI with a relative weight of 0.7118, while those with an MCC assigned will shift to MS-DRG 152 with a weight of 1.0421.

Coding Clinic has also weighed in on the topic of influenza and how it is to be assigned when it occurs with other conditions.  For example, in the 3rd Qtr. 2016 Coding Clinic, a question was asked about the appropriate coding of sepsis when it is due to Influenza B.  The codes that were determined to be correct were A41.89 and J10.1.  

Additional advice from the same issue of Coding Clinic, addressed the conditions of sepsis resulting from influenza with pneumonia.  Here, because the type of influenza was not specified, the codes would be A41.89 for the sepsis, and J11.00 for the influenza.  

Another example comes from the 4th Qtr. 2017 Coding Clinic, where the question was asked about the proper code assignment when a patient had both an acute exacerbation of COPD and a bacterial pneumonia on top of Influenza A.  Here it was determined that four codes were necessary.  J10.08 for the identified influenza with pneumonia; J44.0 for the COPD with acute lower respiratory infection; J15.9 for the bacterial pneumonia; and J44.1 for the acute exacerbation of COPD.  Bear in mind, that for this situation, sequencing of the principal diagnosis would be based on the circumstances of the admission with additional consideration given to the note change that accompanied J44.0 last year. That note changed from “Use an additional code” to identify the infection, meaning that the pneumonia would be sequenced secondarily, to a “Code also” to identify the infection which allows for sequencing of the pneumonia first if appropriate.      

Now you are in the kNOW!!

About the Author 

Dianna Foley, RHIA, CHPS, CCS  is OHIMA's Coding Education Coordinator. Dianna has been an HIM professional for 20 years. She progressed through the ranks of coder, department supervisor, and department director, to her current role as a coding consultant. 

She recently served as the program director for Medical Coding and HIT at Eastern Gateway Community College. Dianna earned her bachelor's degree from the University of Cincinnati subsequently achieving her RHIA, CHPS, and CCS certifications. She is an AHIMA Approved ICD-10-CM/PCS Trainer and a a presenter at regional HIM meetings and the OHIMA Annual Meeting.