2027 ICD-10-CM Diagnosis Code A18.50Tuberculosis of eye, unspecified

ICD-10-CM Codes›A00–B99›A15-A19›A18

ICD-10-CM A18.50
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A18.50 is a billable ICD-10-CM diagnosis code for tuberculosis of eye, unspecified. 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, 974 through 976. 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 20 closely related codes. Coders also document this condition as tuberculosis of eye. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified eye disorders and Tuberculosis.

Code Identity

ICD-10-CM Code
A18.50
Billable Status
Yes — Valid for Submission
Code Describes
Tuberculosis of eye, unspecified
Short Description
Tuberculosis of eye, unspecified
Same as the full description in the CMS dataset.
Parent Code
A18.5
Tuberculosis of eye

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA15-A19Tuberculosis
CategoryA18Tuberculosis of other organs
This CodeA18.50Tuberculosis of eye, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Tuberculosis of eye

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A18.50: its own notes plus those printed at A18.5, block A15-A19, and 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 Block A15-A19 Tuberculosis applies to 51 codes
  • infections due to Mycobacterium tuberculosis and Mycobacterium bovis
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block A15-A19 Tuberculosis applies to 51 codes
  • congenital tuberculosis (P37.0)
  • nonspecific reaction to test for tuberculosis without active tuberculosis (R76.1-)
  • pneumoconiosis associated with tuberculosis, any type in A15 (J65)
  • positive PPD (R76.11)
  • positive tuberculin skin test without active tuberculosis (R76.11)
  • sequelae of tuberculosis (B90.-)
  • silicotuberculosis (J65)

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 A18.5 Tuberculosis of eye applies to 6 codes
  • lupus vulgaris of eyelid (A18.4)
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 Block A15-A19 Tuberculosis applies to 51 codes
  • code, if applicable, for associated cachexia (E88.A)
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.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name A18.50, its category, or a range that includes it.

Applicable To 1

These notes mention A18.50.

  • O98.0 Tuberculosis complicating pregnancy, childbirth and the puerperium
    Conditions in A15-A19 names A15-A19, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming A18.50: its condition is not part of those codes, and both may be reported when the patient has both.

  • A31 Infection due to other mycobacteria
    tuberculosis (A15-A19) names A15-A19, 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.

CCSR EYE012
Other specified eye disorders
Default principal diagnosis: inpatient No · outpatient No
CCSR INF001
Tuberculosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Eye Infections

Your eyes can get infections from bacteria, fungi, or viruses. Eye infections can occur in different parts of the eye and can affect just one eye or both. Two common eye infections are:

Read the full article at MedlinePlus

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

Convert A18.50 to ICD-9-CMHistory

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

ICD-9-CM
017.30 TB of eye-unspec
Approximate The match is approximate rather than exact.

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 A18.50Overview

What is the ICD-10 code for tuberculosis of eye, unspecified?

The ICD-10-CM code for tuberculosis of eye, unspecified is A18.50 (sometimes written as A1850). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A18.50 (Tuberculosis of eye) a billable code?

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

What MS-DRG does A18.50 group to?

When tuberculosis of eye, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 125, 976, 975, 124, with relative weights from 0.7699 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A18.50 a CC or MCC?

CMS lists A18.50 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 20 closely related codes in its exclusion list.

Can A18.50 be reported with P37.0?

Not as a rule. The Excludes1 note at block A15-A19, which applies to A18.50, lists "congenital tuberculosis (P37.0)". 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).