E56 vs T45.2X6
E56 (Other vitamin deficiencies) compared with T45.2X6 (Underdosing of vitamins), 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. T45.2X6 carries an Excludes1 note covering E56: “vitamin deficiencies (E50-E56)”
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
| E56Other vitamin deficiencies | T45.2X6Underdosing of vitamins | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | E00-E89 — Endocrine, Nutritional and Metabolic Diseases (E00-E89) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Other vitamin deficiencies is a non-billable ICD-10-CM category code (E56). | Underdosing of vitamins is a non-billable ICD-10-CM category code (T45.2X6). |
| 7th character | — | The appropriate 7th character is to be added to each code from category T45 |
| Includes | — | 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(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