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L27 vs T78.1

L27 (Dermatitis due to substances taken internally) compared with T78.1 (Other adverse food reactions, not elsewhere classified), 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. L27 carries an Excludes2 note covering T78.1: “adverse food reaction, except dermatitis (T78.0-T78.1)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

Side by side

L27Dermatitis due to substances taken internallyT78.1Other adverse food reactions, not elsewhere classified
Billing statusNon-billable header

Report instead: L27.0, L27.1, L27.2, L27.8, L27.9

Non-billable header

Report instead: T78.110A, T78.110D, T78.110S, T78.111A, T78.111D

ClassificationL00-L99 — Diseases of the Skin and Subcutaneous Tissue (L00-L99)S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
DefinitionDermatitis due to substances taken internally is a non-billable ICD-10-CM category code (L27).Other adverse food reactions, not elsewhere classified is a non-billable ICD-10-CM category code (T78.1).
7th characterThe appropriate 7th character is to be added to each code from category T78
Use additional code
code to identify the type of reaction, if applicable

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources