D84.821 vs T50.911S
D84.821 (Immunodeficiency due to drugs) compared with T50.911S (Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), sequela), 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. T50.911S carries an Excludes2 note covering D84.821: “immunodeficiency due to drugs (D84.821)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Sequencing on the claim
1stD84.821 then T50.911S
D84.821 carries a Use Additional Code instruction covering T50.911S: “code for adverse effect if applicable, to identify adverse effect of drug (T36-T50 with fifth or six character 5)”
Side by side
| D84.821Immunodeficiency due to drugs | T50.911SPoisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), sequela | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | D50-D89 — Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism (D50-D89) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Immunodeficiency due to drugs is a billable ICD-10-CM diagnosis code (D84.821). | Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), sequela is a billable ICD-10-CM diagnosis code (T50.911S). |
| 7th character | — | The appropriate 7th character is to be added to each code from category T50 |
| Includes | defects in the complement system immunodeficiency disorders, except human immunodeficiency virus [HIV] disease sarcoidosis Immunodeficiency due to (current or past) medication | adverse effect of correct substance properly administered poisoning by overdose of substance poisoning by wrong substance given or taken in error underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed |
| Use additional code | code for adverse effect if applicable, to identify adverse effect of drug (T36-T50 with fifth or six character 5) code, if applicable, for associated long term (current) drug therapy drug or medication such as: long term (current) drug therapy systemic steroids (Z79.52) | code(s) to specify: manifestations of poisoning underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9) |
| Code first | — | , for adverse effects, the nature of the adverse effect, such as: adverse effect NOS (T88.7) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources