2027 ICD-10-CM Diagnosis Code A36.3Cutaneous diphtheria

ICD-10-CM Codes›A00–B99›A30-A49›A36

ICD-10-CM A36.3
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A36.3 is a billable ICD-10-CM diagnosis code for cutaneous diphtheria. 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 12 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Skin and subcutaneous tissue infections.

Code Identity

ICD-10-CM Code
A36.3
Billable Status
Yes — Valid for Submission
Code Describes
Cutaneous diphtheria
Short Description
Cutaneous diphtheria
Same as the full description in the CMS dataset.
Parent Code
A36
Diphtheria

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA36Diphtheria
This CodeA36.3Cutaneous diphtheria

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cutaneous diphtheria

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A36.3: its own notes plus those printed at Chapter 1. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

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.

On A36.3 itself
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

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.

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR SKN001
Skin and subcutaneous tissue infections
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Cutaneous Diphtheria

    a usually mild form of diphtheria characterized by infection of the skin by corynebacterium diphtheria and the resulting formation of a chronic, shallow ulcer that is sometimes bordered or followed by a bulla.

  • Diphtheria

    a localized infection of mucous membranes or skin caused by toxigenic strains of corynebacterium diphtheriae. it is characterized by the presence of a pseudomembrane at the site of infection. diphtheria toxin, produced by c. diphtheriae, can cause myocarditis, polyneuritis, and other systemic toxic effects.

Patient EducationClinical

Diphtheria

Diphtheria is a serious bacterial infection. You can catch it from a person who has the infection and coughs or sneezes. You can also get infected by coming in contact with an object, such as a toy, that has bacteria on it.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert A36.3 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
032.85 Cutaneous diphtheria
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A36.3Overview

What is the ICD-10 code for cutaneous diphtheria?

The ICD-10-CM code for cutaneous diphtheria is A36.3 (sometimes written as A363). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A36.3 (Diphtheria) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report cutaneous diphtheria on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does A36.3 group to?

When cutaneous diphtheria 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.

Is A36.3 a CC or MCC?

CMS lists A36.3 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 12 closely related codes in its exclusion list.

What is the ICD-9 equivalent of A36.3?

Under the General Equivalence Mappings, cutaneous diphtheria converts to ICD-9-CM 032.85 (cutaneous diphtheria). The mapping is a direct match.