2027 ICD-10-CM Diagnosis Code A74Other diseases caused by chlamydiae

ICD-10-CM Codes›A00–B99›A70-A74›A74

ICD-10-CM A74
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A74 is a non-billable ICD-10-CM category code for other diseases caused by chlamydiae, so it cannot be submitted on claims. Use a more specific code from this category instead, such as A74.0, A74.81, A74.89, and A74.9.

Code Identity

ICD-10-CM Code
A74
Billable Status
No — Non-Billable Category
Code Describes
Other diseases caused by chlamydiae
Short Description
Other diseases caused by chlamydiae
Same as the full description in the CMS dataset.
Chapter
A70-A74
Other diseases caused by chlamydiae

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA70-A74Other diseases caused by chlamydiae
CategoryA74Other diseases caused by chlamydiae
This CodeA74Other diseases caused by chlamydiae

Specific Coding for Other diseases caused by chlamydiaeOverview

Non-specific codes like A74 require more characters. Use one of these billable codes instead:

  • Use A74.0 for Chlamydial conjunctivitis

  • A74.8 for Other chlamydial diseases

  • Use A74.81 for Chlamydial peritonitis

  • Use A74.89 for Other chlamydial diseases

  • Use A74.9 for Chlamydial infection, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A74: its own notes plus those printed at block A70-A74 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 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.

On A74 itself
  • neonatal chlamydial conjunctivitis (P39.1)
  • neonatal chlamydial pneumonia (P23.1)
  • Reiter's disease (M02.3-)
  • sexually transmitted chlamydial diseases (A55-A56)
From Block A70-A74 Other diseases caused by chlamydiae applies to 8 codes
  • sexually transmitted chlamydial diseases (A55-A56)

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 A74 itself
  • chlamydial pneumonia (J16.0)
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.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name A74, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming A74: its condition is not part of those codes, and both may be reported when the patient has both.

  • A56 Other sexually transmitted chlamydial diseases
    conditions classified to A74.-

Patient EducationClinical

Bacterial Infections

Bacteria are tiny organisms (living things) that have only one cell. Under a microscope, they look like balls, rods, or spirals. They can be found almost everywhere on Earth. There are lots of bacteria in and on your body. In fact, your body has about 10 times more bacteria cells than human cells.

The full article covers:

  • What are bacteria?
  • How do bacterial infections spread?
  • What are the treatments for bacterial infections?
  • Can bacterial infections be prevented?

Read the full article at MedlinePlus

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

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 A74Overview

What is the ICD-10 code for other diseases caused by chlamydiae?

A74 is the ICD-10-CM category for other diseases caused by chlamydiae, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is A74 (Other diseases caused by chlamydiae) a billable code?

No. This is a category header that groups the codes for other diseases caused by chlamydiae, and headers cannot be submitted on claims. Claims for other diseases caused by chlamydiae need a more specific code from this category, such as A74.0, A74.81, and A74.89.

Can A74 be reported with P39.1?

Not as a rule. The Excludes1 note on A74 lists "neonatal chlamydial conjunctivitis (P39.1)". 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).