Bacterial infection of unspecified site (A49) ICD-10-CM
The A49 code range covers bacterial infection of unspecified site with 9 ICD-10-CM diagnosis codes. 7 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- bacterial agents as the cause of diseases classified elsewhere B95 B96
- meningococcal infection NOS A39.9
- rickettsial infection NOS A79.9
- spirochetal infection NOS A69.9
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- chlamydial infection NOS A74.9
Codes in the A49 Range 9 codes · 7 billable
- A49 Bacterial infection of unspecified siteNon-billable
- A49.0 Staphylococcal infection, unspecified siteNon-billable
- A49.01 Methicillin susceptible Staphylococcus aureus infection, unspecified site
- A49.02 Methicillin resistant Staphylococcus aureus infection, unspecified site
- A49.1 Streptococcal infection, unspecified site
- A49.2 Hemophilus influenzae infection, unspecified site
- A49.3 Mycoplasma infection, unspecified site
- A49.8 Other bacterial infections of unspecified site
- A49.9 Bacterial infection, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the A49 range.
Bacterial Infections
Infections by bacteria, general or unspecified.
Methicillin-Resistant Staphylococcus Aureus Infection
A bacterial infection that is caused by Staphylococcus aureus that is not susceptible to methicillin.
Mycoplasma Infections
Infections with species of the genus MYCOPLASMA.
Staphylococcal Infections
Infections with bacteria of the genus STAPHYLOCOCCUS.
Streptococcal Infections
Infections with bacteria of the genus STREPTOCOCCUS.
About the A49 Code Range
These infections involve bacteria, but the site of infection is not specified. The subdivisions distinguish the bacteria named in the diagnosis.
A49.0 covers staphylococcal infection. Its more specific codes distinguish whether Staphylococcus aureus is susceptible or resistant to methicillin. A49.1, A49.2, and A49.3 name other bacteria. A49.8 covers other bacterial infections of unspecified site; A49.9 leaves the bacterial infection unspecified.
Questions About This Page
How many billable codes are in the A49 range?
Of the 9 codes in this range, 7 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the A49 range classify?
The range classifies bacterial infection of unspecified site. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
