ICD-10 Code Z21

Asymptomatic human immunodeficiency virus [HIV] infection status

Version 2019 Billable Code Questionable Admission Codes

Valid for Submission

Z21 is a billable code used to specify a medical diagnosis of asymptomatic human immunodeficiency virus [hiv] infection status. The code is valid for the year 2020 for the submission of HIPAA-covered transactions.

ICD-10: Z21
Short Description:Asymptomatic human immunodeficiency virus infection status
Long Description:Asymptomatic human immunodeficiency virus [HIV] infection status

Code Classification

  • Factors influencing health status and contact with health services (Z00–Z99)
    • Persons with potential health hazards related to communicable diseases (Z20-Z29)
      • Asymptomatic human immunodeficiency virus infection status (Z21)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (first year ICD-10-CM implemented into the HIPAA mandated code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Medical Professionals

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10 Code Edits are applicable to this code:

  • Questionable admission codes - Some diagnoses are not usually sufficient justification for admission to an acute care hospital. For example, if a patient is given code R030 for elevated blood pressure reading, without diagnosis of hypertension, then the patient would have a questionable admission, since elevated blood pressure reading is not normally sufficient justification for admission to a hospital.

Diagnostic Related Groups

The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC). The diagnosis code Z21 is grouped in the following groups for version MS-DRG V37.0 applicable from 10/01/2020 through 09/30/2020.

  • 865 - VIRAL ILLNESS WITH MCC
  • 866 - VIRAL ILLNESS WITHOUT MCC

Convert Z21 to ICD-9

The following crosswalk between ICD-10 to ICD-9 is based based on the General Equivalence Mappings (GEMS) information:

  • V08 - Asymp hiv infectn status

Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Asymptomatic human immunodeficiency virus A1 infection
  • Asymptomatic human immunodeficiency virus A2 infection
  • Asymptomatic human immunodeficiency virus infection
  • Asymptomatic human immunodeficiency virus infection
  • Asymptomatic human immunodeficiency virus infection in pregnancy
  • Finding of HIV status
  • History of asymptomatic human immunodeficiency virus infection
  • HIV positive
  • Human immunodeficiency virus 2 antibody positive and Human immunodeficiency virus 1 antibody cross-reactivity
  • Human immunodeficiency virus antibody positive
  • Human immunodeficiency virus antibody titer - finding
  • Human immunodeficiency virus carrier
  • Human immunodeficiency virus complicating pregnancy childbirth and the puerperium
  • Human immunodeficiency virus enzyme-linked immunosorbent assay test positive
  • Increased human immunodeficiency virus viral load

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code Z21 are found in the index:


Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references for the code Z21 are found in the tabular index:

  • Inclusion Terms:
    • HIV positive NOS
  • Type 1 Excludes Notes:
    • acquired immunodeficiency syndrome (B20)
    • contact WITH human immunodeficiency virus [HIV] (Z20.6)
    • exposure to human immunodeficiency virus [HIV] (Z20.6)
    • human immunodeficiency virus [HIV] disease (B20)
    • inconclusive laboratory evidence of human immunodeficiency virus [HIV] (R75)
  • Code First:
    • Human immunodeficiency virus [HIV] disease complicating pregnancy, childbirth and the puerperium, if applicable (O98.7-)

Information for Patients


HIV/AIDS

HIV stands for human immunodeficiency virus. It harms your immune system by destroying the white blood cells that fight infection. This puts you at risk for serious infections and certain cancers. AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. Not everyone with HIV develops AIDS.

HIV most often spreads through unprotected sex with a person who has HIV. It may also spread by sharing drug needles or through contact with the blood of a person who has HIV. Women can give it to their babies during pregnancy or childbirth.

The first signs of HIV infection may be swollen glands and flu-like symptoms. These may come and go within two to four weeks. Severe symptoms may not appear until months or years later.

A blood test can tell if you have HIV infection. Your health care provider can do the test, or you can use a home testing kit. Or to find free testing sites, call the national referral hotline at 1-800-CDC-INFO (1-800-232-4636 in English and en español; 1-888-232-6348 - TTY).

There is no cure, but there are many medicines that fight HIV infection and lower the risk of infecting others. People who get early treatment can live with the disease for a long time.

Strategies to reduce the risk of HIV infection include not having sex, limiting your number of sexual partners, never sharing needles, and using condoms the right way every time you have sex. People who are at high risk may take HIV prevention medicines.


[Learn More]

ICD-10 Footnotes

General Equivalence Map Definitions
The ICD-10 and ICD-9 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.

  • Approximate Flag - The approximate flag is on, indicating that the relationship between the code in the source system and the code in the target system is an approximate equivalent.
  • No Map Flag - The no map flag indicates that a code in the source system is not linked to any code in the target system.
  • Combination Flag - The combination flag indicates that more than one code in the target system is required to satisfy the full equivalent meaning of a code in the source system.

Index of Diseases and Injuries Definitions

  • And - The word "and" should be interpreted to mean either "and" or "or" when it appears in a title.
  • Code also note - A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.
  • Code first - Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
  • Type 1 Excludes Notes - A type 1 Excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • Type 2 Excludes Notes - A type 2 Excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
  • Includes Notes - This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
  • Inclusion terms - List of terms is included under some codes. These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • NEC "Not elsewhere classifiable" - This abbreviation in the Alphabetic Index represents "other specified". When a specific code is not available for a condition, the Alphabetic Index directs the coder to the "other specified” code in the Tabular List.
  • NOS "Not otherwise specified" - This abbreviation is the equivalent of unspecified.
  • See - The "see" instruction following a main term in the Alphabetic Index indicates that another term should be referenced. It is necessary to go to the main term referenced with the "see" note to locate the correct code.
  • See Also - A "see also" instruction following a main term in the Alphabetic Index instructs that there is another main term that may also be referenced that may provide additional Alphabetic Index entries that may be useful. It is not necessary to follow the "see also" note when the original main term provides the necessary code.
  • 7th Characters - Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.
  • With - The word "with" should be interpreted to mean "associated with" or "due to" when it appears in a code title, the Alphabetic Index, or an instructional note in the Tabular List. The word "with" in the Alphabetic Index is sequenced immediately following the main term, not in alphabetical order.