B20 vs D89.40
B20 (Human immunodeficiency virus [HIV] disease) compared with D89.40 (Mast cell activation, unspecified), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).
Can these codes be reported together?
Yes, when both are documented. D89.40 carries an Excludes2 note covering B20: “human immunodeficiency virus [HIV] disease (B20)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| B20Human immunodeficiency virus [HIV] disease | D89.40Mast cell activation, unspecified | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) | D50-D89 — Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism (D50-D89) |
| Definition | Human immunodeficiency virus [HIV] disease is a billable ICD-10-CM diagnosis code (B20). | Mast cell activation, unspecified is a billable ICD-10-CM diagnosis code (D89.40). |
| Includes | acquired immune deficiency syndrome [AIDS] AIDS-related complex [ARC] HIV infection, symptomatic | defects in the complement system immunodeficiency disorders, except human immunodeficiency virus [HIV] disease sarcoidosis Mast cell activation disorder, unspecified |
| Use additional code | code(s) to identify all manifestations of HIV infection | — |
| Code first | Human immunodeficiency virus [HIV] disease complicating pregnancy, childbirth and the puerperium, if applicable (O98.7-) | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources