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L25 vs T78.41XD

L25 (Unspecified contact dermatitis) compared with T78.41XD (Arthus phenomenon, subsequent encounter), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Relationship

Conflict

Excludes1 conflict

T78.41XD
Arthus phenomenon, subsequent encounter
L25
Unspecified contact dermatitis

Not coded here — these two are mutually exclusive.

“dermatitis (L23-L25, L27.-)”

An Excludes1 note means the two conditions cannot occur together, so the pair should not be reported for the same encounter. The sole exception is when the conditions are documented as unrelated to each other.

Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a

Can these codes be reported together?

No — do not report together. T78.41XD carries an Excludes1 note covering L25: “dermatitis (L23-L25, L27.-)”

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

L25Unspecified contact dermatitisT78.41XDArthus phenomenon, subsequent encounter
Billing statusNon-billable header

Report instead: L25.0, L25.1, L25.2, L25.3, L25.4

Billable
ClassificationL00-L99 — Diseases of the Skin and Subcutaneous Tissue (L00-L99)S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
DefinitionUnspecified contact dermatitis is a non-billable ICD-10-CM category code (L25).Arthus phenomenon, subsequent encounter is a billable ICD-10-CM diagnosis code (T78.41D).
7th characterThe appropriate 7th character is to be added to each code from category T78
Includes
Arthus reaction

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