T67.6XXD vs T88.3
T67.6XXD (Heat fatigue, transient, subsequent encounter) compared with T88.3 (Malignant hyperthermia due to anesthesia), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. T67.6XXD carries an Excludes1 note covering T88.3: “malignant hyperpyrexia due to anesthesia (T88.3)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| T67.6XXDHeat fatigue, transient, subsequent encounter | T88.3Malignant hyperthermia due to anesthesia | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Heat fatigue, transient, subsequent encounter is a billable ICD-10-CM diagnosis code (T67.6D). | Malignant hyperthermia due to anesthesia is a non-billable ICD-10-CM category code (T88.3). |
| 7th character | The appropriate 7th character is to be added to each code from category T67 | The appropriate 7th character is to be added to each code from category T88 |
| Use additional code | — | code for adverse effect, if applicable, to identify drug (T41.- with fifth or sixth character 5) code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) code(s) to identify the specified condition resulting from the complication |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources