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A49.9 ICD-10-CM Code: Bacterial infection, unspecified

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Other bacterial diseases (A30-A49)

A49.9

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Bacterial infection, unspecified

This code is used when a patient has a bacterial infection somewhere in their body, but the specific type of bacteria or the exact location of the infection has not been identified or documented. It serves as a placeholder diagnosis when more specific information is not available.

CMS-HCC V28

0

0

RAF 0

CMS-HCC V24

0

0

RAF 0

ACA/HHS

0

0

RAF 0

ESRD/PACE

0

0

RAF 0

RXHCC

0

0

RAF 0

Code Trumping

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Code Book Path

Official
A49Bacterial infection of unspecified site
A49.9Bacterial infection, unspecified

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for A49.9 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for A49.9 in this effective period.

Related Child Codes

Official
A49.0Staphylococcal infection, unspecified site
A49.1Streptococcal infection, unspecified site
A49.2Hemophilus influenzae infection, unspecified site
A49.3Mycoplasma infection, unspecified site
A49.8Other bacterial infections of unspecified site

Includes

Official

ICD-10-CM does not list Includes notes for A49.9 in this effective period.

Excludes 1

Official
  • bacteremia NOS (R78.81)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for A49.9 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for A49.9 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for A49.9 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
Use this code only when the documentation does not specify the type of bacteria or site of infection; always attempt to obtain more specific diagnostic information before coding
This is a non-specific code that may trigger audits or denials; query the provider for culture results, site of infection, or organism identification to assign a more specific code

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is A49.9 an HCC code?

No. A49.9 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

Coder workflow notes

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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

A49.9 is the ICD-10-CM diagnosis code for bacterial infection, unspecified. This code is used when a patient has a bacterial infection somewhere in their body, but the specific type of bacteria or the exact location of the infection has not been identified or documented. It serves as a placeholder diagnosis when more specific information is not available. A49.9 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering other bacterial diseases (a30-a49).

A49.9 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Use this code only when the documentation does not specify the type of bacteria or site of infection; always attempt to obtain more specific diagnostic information before coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A49.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Use this code only when the documentation does not specify the type of bacteria or site of infection; always attempt to obtain more specific diagnostic information before coding
  • This is a non-specific code that may trigger audits or denials; query the provider for culture results, site of infection, or organism identification to assign a more specific code

Excludes 1, Do NOT code together

Child Codes

Code Hierarchy

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