2026 ICD-10-CM Diagnosis Code A49.3Mycoplasma infection, unspecified site

ICD-10-CM Codes›A00–B99›A30-A49›A49

ICD-10-CM A49.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A49.3 is a billable ICD-10-CM diagnosis code for mycoplasma infection, unspecified site. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869. Coders also document this condition as infection caused by Mycoplasma pneumoniae. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections.

Code Identity

ICD-10-CM Code
A49.3
Billable Status
Yes — Valid for Submission
Code Describes
Mycoplasma infection, unspecified site
Short Description
Mycoplasma infection, unspecified site
Same as the full description in the CMS dataset.
Parent Code
A49
Bacterial infection of unspecified site

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA30-A49Other bacterial diseases
CategoryA49Bacterial infection of unspecified site
This CodeA49.3Mycoplasma infection, unspecified site

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Infection caused by Mycoplasma pneumoniae
  • Infertility due to infection
  • Male infertility due to Mycoplasma infection
  • Mycoplasma genitalium infection
  • Mycoplasma infection
  • Mycoplasmal anemia
  • Mycoplasmal postabortal fever
  • Mycoplasmal postpartum fever
  • Pelvic inflammatory disease caused by Metamycoplasma hominis
  • Puerperal pyrexia

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Infection, infected, infective(opportunistic)
      • Mycoplasma NEC
    • Infection, infected, infective(opportunistic)
      • pleuro-pneumonia-like organism (PPLO) NEC

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient Yes · outpatient Yes

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.

Convert A49.3 to ICD-9-CMHistory

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

ICD-9-CM
041.81 Mycoplasma
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A49.3Overview

Is A49.3 (Bacterial infection of unspecified site) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report mycoplasma infection, unspecified site on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A49.3 group to?

When mycoplasma infection, unspecified site is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, with relative weights from 0.7297 to 2.0932 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A49.3?

Under the General Equivalence Mappings, mycoplasma infection, unspecified site converts to ICD-9-CM 041.81 (mycoplasma). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.