2027 ICD-10-CM Diagnosis Code L23.9Allergic contact dermatitis, unspecified cause
ICD-10-CM Codes›L00–L99›L20-L30›L23
- Billable — Valid for Submission
- Not Chronic
L23.9 is a billable ICD-10-CM diagnosis code for allergic contact dermatitis, unspecified cause. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 606 through 607. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Allergic reactions and Contact dermatitis.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Allergic contact dermatitis
- Allergic contact dermatitis of external auditory canal
- Allergic contact dermatitis of face
- Allergic contact dermatitis of female genitalia
- Allergic contact dermatitis of foot
- Allergic contact dermatitis of hands
- Allergic contact dermatitis of lower leg
- Allergic contact dermatitis of male genitalia
- Allergic contact dermatitis of neck
- Allergic contact dermatitis of perianal skin
- Allergic contact dermatitis of scalp
- Allergic contact sensitization of skin and skin-associated mucous membrane
- Allergic contact urticaria
- Allergic disorder of skin
- Allergic sensitization
- Allergic vulvitis
- Chronic contact dermatitis
- Contact dermatitis of external ear
- Contact dermatitis of female genitalia
- Contact dermatitis of foot
- Contact dermatitis of lower leg
- Contact dermatitis of male genitalia
- Contact dermatitis of neck
- Contact dermatitis of perianal skin
- Contact dermatitis of scalp
- Contact dermatitis of skin of left hand
- Contact dermatitis of skin of right hand
- Contact urticaria
- Disseminated allergic contact urticaria
- Exacerbation of constitutional dermatitis due to occupation
- Exacerbation of constitutional dermatitis due to occupational exposure to contact allergen
- Lichen simplex chronicus
- Lichenoid allergic contact dermatitis
- Lichenoid allergic contact reaction
- Localized allergic contact urticaria
- Occupational allergic contact dermatitis
- Occupational allergic contact sensitization
- Perianal dermatitis
- Protein contact dermatitis
- Systemic contact dermatitis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to L23.9: its own notes plus those printed at L23, block L20-L30, and Chapter 12. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Allergic contact eczema NOS
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- lipomelanotic reticulosis (I89.8)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- systemic connective tissue disorders (M30-M36)
- viral warts (B07.-)
Notes
General instructions on how these codes are used.
- In this block the terms dermatitis and eczema are used synonymously and interchangeably.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name L23.9, its category, or a range that includes it.
Excludes1 4
These codes carry an Excludes1 note naming L23.9: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 3
These codes carry an Excludes2 note naming L23.9: its condition is not part of those codes, and both may be reported when the patient has both.
Code First 2
These codes say to code first a condition named in the note, and L23.9 is one of the conditions named.
- F54 Psychological and behavioral factors associated with disorders or diseases classified elsewhere
- Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Dermatitis, Allergic Contact
a contact dermatitis due to allergic sensitization to various substances. these substances subsequently produce inflammatory reactions in the skin of those who have acquired hypersensitivity to them as a result of prior exposure.
Patient EducationClinical
Allergy
An allergy is a reaction by your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert L23.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About L23.9Overview
What is the ICD-10 code for allergic contact dermatitis, unspecified cause?
The ICD-10-CM code for allergic contact dermatitis, unspecified cause is L23.9 (sometimes written as L239). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is L23.9 (Allergic contact dermatitis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report allergic contact dermatitis, unspecified cause on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does L23.9 group to?
When allergic contact dermatitis, unspecified cause is the principal diagnosis on an inpatient stay, it groups to MS-DRG 607, 606, with relative weights from 0.8772 to 1.5721 depending on complications. Higher weights mean higher Medicare reimbursement.
Can L23.9 be reported with T78.40?
Not as a rule. The Excludes1 note at L23, which applies to L23.9, lists "allergy NOS (T78.40)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of L23.9?
Under the General Equivalence Mappings, allergic contact dermatitis, unspecified cause converts to ICD-9-CM 692.9 (dermatitis NOS). The mapping is approximate, so confirm the match fits the documentation.
