What is ICD-10 code A41.1?

A41.1 is the ICD-10-CM diagnosis code for Sepsis due to other specified staphylococcus. It belongs to the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99). A41.1 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. A41.1 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. A41.1 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. A41.1 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 A41.1?

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 A41.1, V28 maps to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock at RAF 0.455 while V24 mapped to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock at RAF 0.455. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting A41.1?

Ensure the documentation specifically identifies the staphylococcus species involved; if it's methicillin-resistant S. aureus (MRSA) or S. aureus, use more specific codes (A41.01 or A41.02) instead Sepsis codes require a secondary code for the source of infection when documented; verify the clinical record identifies which staphylococcus species is responsible to support code selection Because A41.1 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.

A41.1: Sepsis due to other specified staphylococcus — ICD-10 | Septicemia, Sepsis, Systemic

ICD-10-CM Code View

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

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

A41.1

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

Sepsis due to other specified staphylococcus

A serious bloodstream infection caused by a type of staphylococcus bacteria other than the most common strains (like MRSA or aureus). This condition requires immediate medical treatment as the bacteria has spread throughout the body and triggered a severe inflammatory response.

Buddy Insight

Sepsis due to other specified staphylococcus captures bloodstream infections caused by coagulase-negative staphylococci (CoNS) such as S.

CMS-HCC V28

Mapped

HCC 2

Septicemia, Sepsis, Systemic ...

RAF 0.455

CMS-HCC V24

Mapped

HCC 2

Septicemia, Sepsis, Systemic ...

RAF 0.455

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 2

Septicemia, Sepsis, Systemic ...

RAF 0.0

RXHCC

Not risk-adjusted for this model/period.

RAF 0

Code Trumping

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Code Book Path

Official

A41Other sepsis

A41.1Sepsis due to other specified staphylococcus

Inclusion Terms

Official

Coagulase negative staphylococcus sepsis

Excludes 2

Official

sepsis (due to) (in) actinomycotic (A42.7)
sepsis (due to) (in) anthrax (A22.7)
sepsis (due to) (in) candidal (B37.7)
sepsis (due to) (in) Erysipelothrix (A26.7)
sepsis (due to) (in) extraintestinal yersiniosis (A28.2)

Related Child Codes

Official

A41.0Sepsis due to Staphylococcus aureus

A41.2Sepsis due to unspecified staphylococcus

A41.3Sepsis due to Hemophilus influenzae

A41.4Sepsis due to anaerobes

A41.5Sepsis due to other Gram-negative organisms

Includes

Official

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

Excludes 1

Official

bacteremia NOS (R78.81)
neonatal (P36.-)
puerperal sepsis (O85)
streptococcal sepsis (A40.-)

Code First

Official

, if applicable, postprocedural sepsis (T81.44-)
sepsis due to central venous catheter (T80.211-)
sepsis during labor (O75.3)
sepsis following abortion, ectopic or molar pregnancy (O03.37, O03.87, O04.87, O07.37, O08.82)
sepsis following immunization (T88.0-)

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for A41.1 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for A41.1 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Blood cultures identifying a specific staphylococcal species other than S. aureus

Clinical correlation distinguishing true infection from contamination (multiple positive cultures, clinical signs of sepsis)

Source identification (central venous catheter, prosthetic device, surgical site)

Documentation that the provider considers the positive culture clinically significant, not a contaminant

MEAT Support

HCC Buddy guidance

Blood cultures identifying a specific staphylococcal species other than S. aureus

Clinical correlation distinguishing true infection from contamination (multiple positive cultures, clinical signs of sepsis)

Source identification (central venous catheter, prosthetic device, surgical site)

Documentation that the provider considers the positive culture clinically significant, not a contaminant

Audit Caution

HCC Buddy guidance

Coagulase-negative staph in a single blood culture is often a contaminant — require 2+ positive cultures or clear clinical correlation before coding sepsis

S. lugdunensis behaves more like S. aureus (aggressive, endocarditis-causing) despite being coagulase-negative — ensure appropriate clinical management coding

If the staphylococcal species is truly unknown, use A41.2 (unspecified), not A41.1

Always assess for and code device-related infections when CoNS bacteremia is documented

Common Mistakes

HCC Buddy guidance

A41.01/A41.02 (MSSA/MRSA sepsis) — Those codes are specifically for S. aureus; A41.1 is for all other staphylococcal species

A41.2 (Sepsis due to unspecified staphylococcus) — Use A41.1 when the specific CoNS species is identified

T80.211A (Bloodstream infection due to central venous catheter) — Code the catheter infection separately if applicable, in addition to A41.1

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 A41.1 an HCC code?

Yes. A41.1 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).

HCC Category Mapping

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

0.455

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

0.455

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

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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 A41.1 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for A41.1

For A41.1to 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 A41.1 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

A41.1 is the ICD-10-CM diagnosis code for sepsis due to other specified staphylococcus. A serious bloodstream infection caused by a type of staphylococcus bacteria other than the most common strains (like MRSA or aureus). This condition requires immediate medical treatment as the bacteria has spread throughout the body and triggered a severe inflammatory response. A41.1 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, A41.1 maps to Septicemia, Sepsis, Systemic Inflammatory Response Syndrome/Shock (HCC 2) with a community, non-dual, aged base RAF weight of 0.455. The V24 model used during the PY2024–PY2025 transition mapped A41.1 the same way and at the same RAF weight. 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.

Ensure the documentation specifically identifies the staphylococcus species involved; if it's methicillin-resistant S. aureus (MRSA) or S. aureus, use more specific codes (A41.01 or A41.02) instead. Because A41.1 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 A41.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Ensure the documentation specifically identifies the staphylococcus species involved; if it's methicillin-resistant S. aureus (MRSA) or S. aureus, use more specific codes (A41.01 or A41.02) instead
•Sepsis codes require a secondary code for the source of infection when documented; verify the clinical record identifies which staphylococcus species is responsible to support code selection

Clinical Significance

Sepsis due to other specified staphylococcus captures bloodstream infections caused by coagulase-negative staphylococci (CoNS) such as S. epidermidis, S. lugdunensis, and S. saprophyticus. While often considered contaminants, true CoNS bacteremia is increasingly recognized as a significant cause of prosthetic device infections, central line-associated bloodstream infections, and native valve endocarditis (especially S. lugdunensis).

Documentation Requirements

✓Blood cultures identifying a specific staphylococcal species other than S. aureus
✓Clinical correlation distinguishing true infection from contamination (multiple positive cultures, clinical signs of sepsis)
✓Source identification (central venous catheter, prosthetic device, surgical site)
✓Documentation that the provider considers the positive culture clinically significant, not a contaminant
✓Susceptibility testing results, as CoNS are frequently methicillin-resistant

Commonly Confused Codes

•A41.01/A41.02 (MSSA/MRSA sepsis): Those codes are specifically for S. aureus; A41.1 is for all other staphylococcal species
•A41.2 (Sepsis due to unspecified staphylococcus): Use A41.1 when the specific CoNS species is identified
•T80.211A (Bloodstream infection due to central venous catheter): Code the catheter infection separately if applicable, in addition to A41.1