Question 1

Is Z21 a billable ICD-10 code?

Accepted Answer

Yes, Z21 is a valid billable ICD-10-CM code for asymptomatic human immunodeficiency virus [hiv] infection status. It can be used for medical billing and reimbursement purposes.

Question 2

What does ICD-10 code Z21 mean?

Accepted Answer

ICD-10-CM code Z21 represents Asymptomatic human immunodeficiency virus [HIV] infection status. This code is part of the International Classification of Diseases, 10th Revision, Clinical Modification used for medical coding and billing in the United States.

Question 3

When was ICD-10 code Z21 introduced?

Accepted Answer

Code Z21 has been part of ICD-10-CM since 2016, when the coding system was mandated for use in the United States. This code was included in the original US implementation.

Question 4

What is the parent category for ICD-10 code Z21?

Accepted Answer

The parent category for Z21 is section:Z20-Z29 (Persons with potential health hazards related to communicable diseases (Z20-Z29)). This hierarchical classification helps organize related diagnoses for more accurate coding.

Question 5

What conditions are excluded from Z21?

Accepted Answer

Code Z21 has Type 1 Excludes (mutually exclusive conditions) including: acquired immunodeficiency syndrome (B20); contact with human immunodeficiency virus [HIV] (Z20.6); exposure to human immunodeficiency virus [HIV] (Z20.6) and 2 more conditions. These conditions cannot be coded together with Z21 as they represent different diagnoses.

Question 6

Is Z21 sufficient for hospital admission?

Accepted Answer

Code Z21 is flagged as a "questionable admission" diagnosis by the Medicare Code Editor. This means it is usually not sufficient justification for admission to an acute care hospital. Claims with this code as principal diagnosis may be reviewed for medical necessity.

Z212026

Excludes15Not coded together

Code First1Sequence another code first

Notes4Additional information

Also Known As10Alternative terms

Medicare Code Editor Rules1CMS coding restrictions