2027 ICD-10-CM Diagnosis Code A36.86Diphtheritic conjunctivitis

ICD-10-CM Codes›A00–B99›A30-A49›A36

ICD-10-CM A36.86
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A36.86 is a billable ICD-10-CM diagnosis code for diphtheritic conjunctivitis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 124 through 125. 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. Coders also document this condition as acute toxic conjunctivitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Cornea and external disease.

Code Identity

ICD-10-CM Code
A36.86
Billable Status
Yes — Valid for Submission
Code Describes
Diphtheritic conjunctivitis
Short Description
Diphtheritic conjunctivitis
Same as the full description in the CMS dataset.
Parent Code
A36.8
Other diphtheria

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA36Diphtheria
This CodeA36.86Diphtheritic conjunctivitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute toxic conjunctivitis
  • Conjunctival diphtheria
  • Membranous conjunctivitis
  • Ocular diphtheria
  • Pseudomembranous conjunctivitis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A36.86: 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.

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 EYE001
Cornea and external disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • 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 A36.86 to ICD-9-CMHistory

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

ICD-9-CM
032.81 Conjunctival 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 A36.86Overview

What is the ICD-10 code for diphtheritic conjunctivitis?

The ICD-10-CM code for diphtheritic conjunctivitis is A36.86 (sometimes written as A3686). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A36.86 (Other diphtheria) a billable code?

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

What MS-DRG does A36.86 group to?

When diphtheritic conjunctivitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 125, 124, with relative weights from 0.7699 to 1.2470 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A36.86 a CC or MCC?

CMS lists A36.86 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 A36.86?

Under the General Equivalence Mappings, diphtheritic conjunctivitis converts to ICD-9-CM 032.81 (conjunctival diphtheria). The mapping is a direct match.