ICD-10-CM 2027
ICD-10 code for iris erythema
From the official ICD-10-CM alphabetic index entry “Erythema, erythematous (infectional) (inflammation) › iris”. Page updated September 29, 2026.
About coding iris erythema
The ICD-10-CM code for iris erythema is L51.9 (Erythema multiforme, unspecified).
Within L51, choose L51.9 (unspecified) only when documentation doesn't support a more specific option: Nonbullous erythema multiforme (L51.0), Stevens-Johnson syndrome (L51.1), toxic epidermal necrolysis [Lyell] (L51.2), Stevens-Johnson syndrome-toxic epidermal necrolysis overlap syndrome (L51.3) and other erythema multiforme (L51.8).
Use an additional code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5). Use an additional code to identify associated manifestations, such as: arthropathy associated with dermatological disorders (M14.8-), conjunctival edema (H11.42), conjunctivitis (H10.22-), corneal scars and opacities (H17.-), corneal ulcer (H16.0-) and 7 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Common questions about iris erythema ICD-10 codes
What is the ICD-10 code for iris erythema?
- L51.9 — Erythema multiforme, unspecified.
Is L51.9 billable?
- Yes. L51.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can L51.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict L51.9 as a principal diagnosis.
Is L51.9 a CC or MCC?
- No. L51.9 is neither a CC nor an MCC under MS-DRG v44.0.