2027 ICD-10-CM Diagnosis Code L27.9Dermatitis due to unspecified substance taken internally
ICD-10-CM Codes›L00–L99›L20-L30›L27
- Billable — Valid for Submission
- Not Chronic
L27.9 is a billable ICD-10-CM diagnosis code for dermatitis due to unspecified substance taken internally. 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. Coders also document this condition as baboon syndrome. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Allergic reactions and Other specified inflammatory condition of skin.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Baboon syndrome
- Dermatitis caused by substance taken via oral route
- Intertrigo
- Localized dermatitis caused by substance taken via oral route
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to L27.9: its own notes plus those printed at L27, block L20-L30, and Chapter 12. A note printed at a category, block or chapter applies to every code under it.
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 L27.9, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming L27.9: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 3
These codes carry an Excludes2 note naming L27.9: its condition is not part of those codes, and both may be reported when the patient has both.
- L23 Allergic contact dermatitisdermatitis due to substances taken internally (L27.-) names L27.-, which includes this code
- L24 Irritant contact dermatitisdermatitis due to substances taken internally (L27.-) names L27.-, which includes this code
- L25 Unspecified contact dermatitisdermatitis due to ingested substances (L27.-) names L27.-, which includes this code
Code First 1
These codes say to code first a condition named in the note, and L27.9 is one of the conditions named.
- Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substancesdermatitis due to substances taken internally (L27.-) names L27.-, which includes this code
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 due to Unspecified Substance Taken Internally
dermatitis caused by an allergic reaction to an unspecified ingested substance.
Patient EducationClinical
Rashes
A rash is an area of irritated or swollen skin. Many rashes are itchy, red, painful, and irritated. Some rashes can also lead to blisters or patches of raw skin. Rashes are a symptom of many different medical problems. Other causes include irritating substances and allergies. Certain genes can make people more likely to get rashes.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert L27.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About L27.9Overview
What is the ICD-10 code for dermatitis due to unspecified substance taken internally?
The ICD-10-CM code for dermatitis due to unspecified substance taken internally is L27.9 (sometimes written as L279). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is L27.9 (Dermatitis due to substances taken internally) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report dermatitis due to unspecified substance taken internally on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does L27.9 group to?
When dermatitis due to unspecified substance taken internally 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 L27.9 be reported with T78.40?
Not as a rule. The Excludes1 note at L27, which applies to L27.9, 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 L27.9?
Under the General Equivalence Mappings, dermatitis due to unspecified substance taken internally converts to ICD-9-CM 693.9 (dermat d/t int agent NOS). The mapping is a direct match.
