D84.822

Billable

Immunodeficiency due to external causes

HCC Category Mapping

V24HCC 47 — Disorders of Immunity

0.472

ESRDHCC 47 — Disorders of Immunity

0.000

RxHCCHCC 99 — Immunodeficiencies

0.000

What This Code Means

A weakened immune system caused by external factors such as radiation therapy, severe malnutrition, or environmental exposure.

Coding Tips

•Identify and document the specific external cause (radiation, malnutrition, etc.)
•May require an external cause code (Chapter 20) depending on the circumstances

Clinical Significance

Immunodeficiency due to external causes represents immune system compromise resulting from environmental or external exposures such as ionizing radiation, severe malnutrition, or toxic chemical exposure. These external factors damage immune cell populations or impair immune function through mechanisms distinct from genetic immunodeficiency or drug-induced immunosuppression.

Documentation Requirements

✓Documentation must identify the specific external cause of immunodeficiency (radiation exposure type and dose, nutritional deficiency specifics, toxic exposure), include evidence of resulting immune dysfunction (lymphopenia, recurrent infections, impaired vaccine responses), and describe the temporal relationship between the external exposure and immune impairment.
✓Assign appropriate external cause codes from Chapter 20.

Use Additional Code

code for external cause such as:
exposure to ionizing radiation (W88)

Code Also

, if applicable, radiological procedure and radiotherapy (Y84.2)

Commonly Confused Codes

D84.821 (immunodeficiency due to drugs, which is pharmaceutical rather than environmental), D84.81 (immunodeficiency due to conditions classified elsewhere, which is disease-related), E46 (unspecified protein-calorie malnutrition which may cause immunodeficiency but should be coded primarily with D84.822 as additional), D84.9 (immunodeficiency, unspecified, which does not identify the external cause).

Code Hierarchy

└D84Other immunodeficiencies └D84.8Other specified immunodeficiencies └D84.82Immunodeficiency due to drugs and external causes └D84.822Immunodeficiency due to external causes

└D84.822Immunodeficiency due to external causes