ICD-10-CM: Latent Tuberculosis


by Lynn Kuehn, MS, RHIA, CCS-P, FAHIMA

Long-awaited codes for the diagnosis of latent tuberculosis (TB) are finally coming to the FY2020 ICD-10-CM code set.

To review, later TB is the presence of mycobacterium tuberculosis in the patient’s body but the bacteria has not grown. Latent TB has no symptoms and can’t be spread to others. The challenging part of latent TB is that it can convert to active tuberculosis disease at any point in the future.

In contrast, active TB is growing inside the patient’s body, causes symptoms, easily spreads to others and can be lethal if untreated. Refer to figure for a comparison.


Let’s look at the coding involved with the various diagnoses of TB.

The testing process still begins with a screening TB skin test even though there are no symptoms. This code continues to be:

Z11.1 Encounter for screening for respiratory tuberculosis

If this screening test is positive, the patient undergoes a chest X-ray or other testing to determine whether the screening result indicated latent TB or active TB. To support the medical necessity for this testing, this new code is assigned:

Z11.7 Encounter for testing for latent tuberculosis infection

The skin test reaction may also be coded with this existing code while testing is taking place:

R76.11 Nonspecific reaction to tuberculin skin test without active TB

If the chest x-ray or other testing is negative, the diagnosis of latent TB will probably be made, coded as the new code:

Z22.7 Latent tuberculosis

If the chest x-ray or other testing is positive, the diagnosis of respiratory tuberculosis will probably be made, coded from existing category A15, based on the documentation, along with any associated conditions or complications.

Both latent TB and active TB are treated, typically with Isoniazid (INH). Once the latent TB is eliminated from the patient’s body, the patient then has a personal history of latent TB, coded as the new code:

Z86.15 Personal history of latent tuberculosis infection

When active TB is eliminated, the patient then has a personal history of TB, coded with the existing code:

Z86.11 Personal history of tuberculosis

In the future, all of these codes together will give us data on the rate of latent TB versus active TB, data that epidemiologists and public health professional will find very helpful.



Now available! FY 2020 ICD-10 Code Updates by nationally recognized coding expert Lynn Kuehn

“Anyone can read what the changes are, but truly understanding what the changes mean, why they were made, and how to ensure compliance going into FY 2020, requires a different approach.”
— Lynn Kuehn, author of the Libman Education ICD-10 CM and PCS Updates courses

About the Author

Lynn Kuehn is president of Kuehn Consulting, LLC, in Waukesha, Wisconsin, a consulting firm specializing in ICD-10-PCS coding for the inpatient setting. Lynn is a nationally recognized trainer on ICD-10-PCS and other HIM-related topics. Lynn served on the AHIMA Board of Directors and authored several of AHIMA’s most popular books including ICD-10-PCS: An Applied Approach and Procedural Coding and Reimbursement for Physician Services. Together with her co-Author Theresa Jorwic, Lynn received the Triumph Literary Legacy Award from AHIMA for ICD-10-PCS: An Applied Approach. Called the “go-to” resource for learning and mastering ICD-10-PCS, ICD-10-PCS: An Applied Approach provides step-by-step instructions and exercises at all levels, and is used throughout Kuehn’s ICD-10-PCS courses authored for Libman Education.

One thought on “ICD-10-CM: Latent Tuberculosis

  1. Nanci Schwindt - August 21, 2019 at 7:23 pm

    Great info, explained so well, as usual for Lynn! Thank you