Part 2: Top 5 ICD-10-CM Chapters 2019

In 2019, HIA reviewed over 725,600 ICD-10-CM codes from many different facilities including reviews on our own coders. Yesterday we looked at the ICD-10-CM Chapter 21 and today we will focus on the second area with the most coding opportunities found during HIA reviews.

  1. Z00-Z99—Factors influencing health status and contact with health services
  2. A00-B99—Certain Infectious and Parasitic Diseases
  3. I00-I99—Disease of the Circulatory System
  4. J00-J99—Diseases of the Respiratory System
  5. E00-E89—Endocrine, Nutritional, and Metabolic Diseases

For Part 2 of this 5-part series, we will look at Chapter 1 within ICD-10-CM—A00-B99—Certain Infectious and Parasitic Diseases. There is no possible way to include every guideline or coding reference for this chapter, but here are some of the most common issues.

Chapter 1: A00-B99—Certain Infectious and Parasitic Diseases:

Chapter 1 in ICD-10-CM has 22 sections. In looking through the recommendations made, it looks like sequencing of sepsis and specificity are the most common recommendations, followed by additions and deletions. However, there is more to this chapter than sepsis. Below are a few areas where coding opportunities were identified during HIA client and internal quality reviews.

  • Sequencing of sepsis or determining if sepsis was present on admission or if there are clinical indicators to support this diagnosis
  • Sepsis is due to a postprocedural infection or device
  • Sepsis being ruled out in the body of the record
  • HIV being reported instead of asymptomatic HIV status
  • Missed query opportunities
  • Confusion with sequencing code of hepatitis, cirrhosis and encephalopathy

In addition to the Official Coding Guidelines for ICD-10-CM for FY 2020, Pages 24-29 that address specific chapter guidelines to follow for reporting infectious and parasitic disease, there are multiple AHA Coding Clinics that discuss some of these in detail. Here are a few of these:

  • ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2017 Pages: 4, 109
  • ICD-10-CM/PCS Coding Clinic, First Quarter 2017 Pages:41,  51
  • ICD-10-CM/PCS Coding Clinic, Third Quarter 2016 Page: 9-14
  • ICD-10-CM/PCS Coding Clinic, First Quarter 2019 Pages: 8-11, 14
  • ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2018 Pages: 16-18 & 89-90
  • ICD-10-CM/PCS Coding Clinic, First Quarter 2016 Pages: 12-13 & 39-40
  • ICD-10-CM/PCS Coding Clinic, First Quarter 2018 Pages: 4-5, 16
  • ICD-10-CM/PCS Coding Clinic, Fourth Quarter 2014 Page: 46
  • ICD-10-CM/PCS Coding Clinic, Second Quarter 2014 Page: 13


Coding Tips for Chapter 1: A00-B99—Certain Infectious and Parasitic Diseases:

  • Use additional codes to identify resistance to antimicrobial drugs
  • Follow all instructional notes within ICD-10-CM for sequencing and to determine if additional codes would be reported
  • Code only confirmed cases of HIV infection/illness
  • B20 (HIV infection) should be reported first when patient is admitted for HIV-related conditions
  • Z21 (asymptomatic HIV infection status) is reported when documentation states “HIV positive,” “known HIV,” “HIV test positive,” or similar terminology
  • Once a patient has developed an HIV-related illness, B20 would always be reported on all subsequent admissions/visits
  • In pregnant patients with HIV, codes from Chapter 15—Pregnancy, Childbirth, and the Puerperium (O00-O9A) always take sequencing priority
  • Severe sepsis should only be coded when severe sepsis is documented by the physician or there is an associated organ system dysfunction in addition to diagnosis of sepsis
  • If the organ failure/dysfunction is not specifically documented to be associated with the diagnosis of sepsis a query would be needed before reporting the diagnosis of severe sepsis
  • Urosepsis has no default code in ICD-10-CM and is not synonymous with the term sepsis
  • If patient admitted with sepsis due to localized infection, the underlying systemic infection (sepsis) should be assigned first followed by a code for the localized infection as a secondary diagnosis
  • Verify that the documentation does not support or suggest that the diagnosis of sepsis is due to  a device or post procedure infection
  • If sepsis is present with a noninfectious condition, such as trauma, and this condition meets the definition for principal diagnosis, the code for the noninfectious condition should be sequenced first followed by the code for the resulting infection
  • If sepsis meets the definition of PDX, it should be sequenced before the associated non-infectious condition. If both the associated non-infectious condition and the infection meet the definition of PDX either may be sequenced as PDX
  • Code only confirmed cases of Zika virus
  • ICD-10-CM code A41.89 (other specified sepsis) is used to report the diagnosis of viral sepsis
  • Do not assign additional bacteria code if the code for sepsis specifies the bacteria—Example: Sepsis due to Escherichia coli UTI. Since the code for E. coli sepsis clearly identifies the bacteria responsible for both conditions, reporting B96.20 (unspecified E. coli) is redundant

Most of the tips above are for sepsis but there are many more diagnosis in this chapter of ICD-10-CM. Sepsis is just a tough area for coders and was our number 1 change for all of 2019.

Authored by Kim Boy, RHIT, CDIP, CCS, CCS-P

The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.

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