What is ICD-10 code A41.54?

A41.54 is the ICD-10-CM diagnosis code for Sepsis due to Acinetobacter baumannii. A serious bloodstream infection caused by the bacterium Acinetobacter baumannii, which can spread throughout the body and cause organ failure. This is a life-threatening condition that requires immediate medical treatment with antibiotics. A41.54 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. A41.54 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. A41.54 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. A41.54 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for A41.54?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For A41.54, V28 maps to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock at RAF 0.500 while V24 mapped to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock at RAF 0.352. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting A41.54?

Verify the sepsis is confirmed as due to Acinetobacter baumannii with documentation of positive blood cultures or clinical evidence; do not assume the organism without explicit provider documentation Remember to code the underlying sepsis condition separately (typically R65.2x) and any associated organ dysfunction codes (such as acute kidney injury, respiratory failure) to capture the full clinical picture and severity Because A41.54 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

2026 ICD-10-CM A41.54: Sepsis due to Acinetobacter

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Code lookupA41.54Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

A41.54

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

Sepsis due to Acinetobacter baumannii

A serious bloodstream infection caused by the bacterium Acinetobacter baumannii, which can spread throughout the body and cause organ failure. This is a life-threatening condition that requires immediate medical treatment with antibiotics.

Buddy Insight

Sepsis due to Acinetobacter baumannii is a feared healthcare-associated infection primarily affecting ICU patients, particularly those on mechanical ventilation or with traumatic injuries.

CMS-HCC V28

Mapped

HCC 2

Septicemia, Sepsis, Systemic ...

RAF 0.500

CMS-HCC V24

Mapped

HCC 2

Septicemia, Sepsis, Systemic ...

RAF 0.352

ACA/HHS

Mapped

HCC 2

HHS-HCC 2

Varies by metal level

ESRD/PACE

Mapped

HCC 2

Septicemia, Sepsis, Systemic ...

RAF 0.087

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

A41Other sepsis

A41.5Sepsis due to other Gram-negative organisms

A41.54Sepsis due to Acinetobacter baumannii

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for A41.54 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for A41.54 in this effective period.

Related Child Codes

Official

A41.50Gram-negative sepsis, unspecified

A41.51Sepsis due to Escherichia coli [E. coli]

A41.52Sepsis due to Pseudomonas

A41.53Sepsis due to Serratia

A41.59Other Gram-negative sepsis

Includes

Official

ICD-10-CM does not list Includes notes for A41.54 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for A41.54 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for A41.54 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for A41.54 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for A41.54 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Blood cultures positive for Acinetobacter baumannii

ICU admission and mechanical ventilation status if applicable

Antibiotic susceptibility results with specific documentation of resistance pattern (carbapenem-resistant, multidrug-resistant, extensively drug-resistant)

Source of infection (ventilator-associated pneumonia, central line, wound, urinary catheter)

MEAT Support

HCC Buddy guidance

Blood cultures positive for Acinetobacter baumannii

ICU admission and mechanical ventilation status if applicable

Antibiotic susceptibility results with specific documentation of resistance pattern (carbapenem-resistant, multidrug-resistant, extensively drug-resistant)

Source of infection (ventilator-associated pneumonia, central line, wound, urinary catheter)

Audit Caution

HCC Buddy guidance

A. baumannii can colonize patients and environmental surfaces for prolonged periods — distinguish true infection from colonization before coding sepsis

If carbapenem-resistant, add Z16.24 (Resistance to multiple antibiotics) or other appropriate Z16 codes

This organism is often part of polymicrobial infections in ICU patients — code all identified organisms

Document whether the infection was present on admission or hospital-acquired for POA indicator purposes

Common Mistakes

HCC Buddy guidance

A41.59 (Other gram-negative sepsis) — A41.54 is the specific code for A. baumannii; do not use the 'other' category

A41.50 (Gram-negative sepsis, unspecified) — Use A41.54 when Acinetobacter is identified

A41.52 (Sepsis due to Pseudomonas) — Both are gram-negative MDROs common in ICUs, but they are different organisms requiring different treatment

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is A41.54 an HCC code?

Yes. A41.54 (Sepsis due to Acinetobacter baumannii) maps to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock under the CMS-HCC V28 risk adjustment model (and Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock under V24), with a community non-dual aged RAF of 0.500. It is billable for payment year 2026.

Coder answer: A41.54 is billable and maps to V28 HCC 2, Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: A41.54
Description: Sepsis due to Acinetobacter baumannii
HCC (V28): HCC 2 — Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock
RAF: 0.500
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 2, Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock

0.500

V24HCC 2, Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock

0.352

ESRDHCC 2, Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock

0.087

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work A41.54 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for A41.54

For A41.54 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed A41.54 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

A41.54 is the ICD-10-CM diagnosis code for sepsis due to acinetobacter baumannii. A serious bloodstream infection caused by the bacterium Acinetobacter baumannii, which can spread throughout the body and cause organ failure. This is a life-threatening condition that requires immediate medical treatment with antibiotics. A41.54 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering other bacterial diseases (a30-a49).

Under the CMS-HCC V28 risk adjustment model, A41.54 maps to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock (HCC 2) with a community, non-dual, aged base RAF weight of 0.500. Under the older V24 model, A41.54 mapped to the same category but with a base RAF weight of 0.352, V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Verify the sepsis is confirmed as due to Acinetobacter baumannii with documentation of positive blood cultures or clinical evidence; do not assume the organism without explicit provider documentation. Because A41.54 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A41.54 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify the sepsis is confirmed as due to Acinetobacter baumannii with documentation of positive blood cultures or clinical evidence; do not assume the organism without explicit provider documentation
•Remember to code the underlying sepsis condition separately (typically R65.2x) and any associated organ dysfunction codes (such as acute kidney injury, respiratory failure) to capture the full clinical picture and severity

Clinical Significance

Sepsis due to Acinetobacter baumannii is a feared healthcare-associated infection primarily affecting ICU patients, particularly those on mechanical ventilation or with traumatic injuries. A. baumannii is a leading multidrug-resistant organism (MDRO) and is classified as an urgent threat by the CDC due to extensive carbapenem resistance, often leaving colistin or novel agents as the only treatment options.

Documentation Requirements

✓Blood cultures positive for Acinetobacter baumannii
✓ICU admission and mechanical ventilation status if applicable
✓Antibiotic susceptibility results with specific documentation of resistance pattern (carbapenem-resistant, multidrug-resistant, extensively drug-resistant)
✓Source of infection (ventilator-associated pneumonia, central line, wound, urinary catheter)
✓Infection control measures and isolation documentation

Commonly Confused Codes

•A41.59 (Other gram-negative sepsis): A41.54 is the specific code for A. baumannii; do not use the 'other' category
•A41.50 (Gram-negative sepsis, unspecified): Use A41.54 when Acinetobacter is identified
•A41.52 (Sepsis due to Pseudomonas): Both are gram-negative MDROs common in ICUs, but they are different organisms requiring different treatment