L23.9 Allergic contact dermatitis, unspecified cause

Billable ICD-10-CM code, FY2026.

Applicable to

• Allergic contact eczema NOS

Applies from L23 Allergic contact dermatitis

Excludes1 (never code together)

• allergy NOS (T78.40)
• contact dermatitis NOS (L25.9)
• dermatitis NOS (L30.9)

Excludes2 (not included here)

• dermatitis due to substances taken internally (L27.-)
• dermatitis of eyelid (H01.1-)
• diaper dermatitis (L22)
• eczema of external ear (H60.5-)
• irritant contact dermatitis (L24.-)
• perioral dermatitis (L71.0)
• radiation-related disorders of the skin and subcutaneous tissue (L55-L59)

MS-DRG index

Defines the logic of DRG(s) 606-607 in MDC 09.

Approximate ICD-9-CM (GEMs)

• 692.9 Contact dermatitis and other eczema, unspecified cause (approximate)

Code annotations containing back-references to L23.9

Back-references to L23

• Code First: F54 Psychological and behavioral factors associated with disorders or diseases classified elsewhere ("dermatitis (L23-L25)")
• Type 2 Excludes: L24 Irritant contact dermatitis ("allergic contact dermatitis (L23.-)")
• Type 1 Excludes: L25 Unspecified contact dermatitis ("allergic contact dermatitis (L23.-)")
• Type 2 Excludes: L27 Dermatitis due to substances taken internally ("contact dermatitis (L23-L25)")
• Type 2 Excludes: L30 Other and unspecified dermatitis ("contact dermatitis (L23-L25)")
• Type 1 Excludes: L50 Urticaria ("allergic contact dermatitis (L23.-)")
• Type 1 Excludes: L53 Other erythematous conditions ("erythema due to external agents in contact with skin (L23-L25)")
• Type 1 Excludes: T78.4 Other and unspecified allergy ("dermatitis (L23-L25, L27.-)")

Diagnosis Index entries for L23.9

• Dermatitis (eczematous) › contact (occupational) › allergic
• Dermatitis (eczematous) › sensitization NOS

Nearby codes

• L23.6 Allergic contact dermatitis due to food in contact with the skin
• L23.7 Allergic contact dermatitis due to plants, except food
• L23.8 Allergic contact dermatitis due to other agents
• L23.81 Allergic contact dermatitis due to animal (cat) (dog) dander
• L23.89 Allergic contact dermatitis due to other agents
• L23.9 Allergic contact dermatitis, unspecified cause (this code)