What is ICD-10 code A20.2?

A20.2 is the ICD-10-CM diagnosis code for Pneumonic plague. It belongs to the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99). A20.2 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. A20.2 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. A20.2 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. A20.2 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 A20.2?

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. A20.2 was a payment HCC under V24 (Pneumococcal Pneumonia, Empyema, Lung Abscess) but the V28 recalibration removed it from the risk adjustment model. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting A20.2?

Pneumonic plague is a reportable disease in most jurisdictions; ensure proper documentation of diagnosis and consider notifying public health authorities as required by law Distinguish between pneumonic plague (A20.2) and other plague forms such as bubonic plague (A20.0) or septicemic plague (A20.7) based on clinical presentation and affected body systems Because A20.2 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.

A20.2: Pneumonic plague — ICD-10 | Pneumococcal Pneumonia, Empyema, Lung Abscess

ICD-10-CM Code View

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Code lookupA20.2Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Certain zoonotic bacterial diseases (A20-A28)

A20.2

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

Pneumonic plague

Pneumonic plague is a severe lung infection caused by the bacterium Yersinia pestis, which is transmitted through respiratory droplets or inhalation of contaminated air. This is the most dangerous form of plague and can spread from person to person, causing rapid onset of respiratory symptoms and potentially fatal complications.

Buddy Insight

Pneumonic plague is the most severe and rapidly fatal form of Yersinia pestis infection, capable of person-to-person airborne transmission.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Mapped

HCC 115

Pneumococcal Pneumonia, Empye...

RAF 0.130

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 115

Pneumococcal Pneumonia, Empye...

RAF 0.0

RXHCC

Not risk-adjusted for this model/period.

RAF 0

Code Trumping

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Code Book Path

Official

A20Plague

A20.2Pneumonic plague

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for A20.2 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for A20.2 in this effective period.

Related Child Codes

Official

A20.0Bubonic plague

A20.1Cellulocutaneous plague

A20.3Plague meningitis

A20.7Septicemic plague

A20.8Other forms of plague

Includes

Official

infection due to Yersinia pestis

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for A20.2 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for A20.2 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for A20.2 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for A20.2 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Clinical presentation consistent with pneumonic plague (severe pneumonia, hemoptysis, sepsis)

Laboratory confirmation — culture, PCR, or serology for Yersinia pestis

Epidemiologic link (endemic area exposure, animal contact, bioterrorism concern)

Chest imaging showing rapidly progressive bilateral pneumonia

MEAT Support

HCC Buddy guidance

Clinical presentation consistent with pneumonic plague (severe pneumonia, hemoptysis, sepsis)

Laboratory confirmation — culture, PCR, or serology for Yersinia pestis

Epidemiologic link (endemic area exposure, animal contact, bioterrorism concern)

Chest imaging showing rapidly progressive bilateral pneumonia

Audit Caution

HCC Buddy guidance

Pneumonic plague can be primary (inhaled) or secondary (spread from bubonic/septicemic) — both are coded A20.2 when pneumonia is present

This is a CDC Category A bioterrorism agent — ensure proper public health reporting codes are considered

Do not delay coding for culture confirmation in a clinically suspected case — clinical diagnosis is sufficient for code assignment

Common Mistakes

HCC Buddy guidance

A20.0 (Bubonic plague) — Bubonic plague presents with lymphadenopathy (buboes); pneumonic plague specifically involves the lungs with pneumonia

A20.7 (Septicemic plague) — Septicemic plague is bloodstream infection without primary pneumonia; can overlap — code both if both documented

J15.9 (Unspecified bacterial pneumonia) — Never use generic pneumonia codes when plague pneumonia is identified

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 A20.2 an HCC code?

Yes. A20.2 maps to Pneumococcal Pneumonia, Empyema, Lung Abscess under the V24 model but is not retained in V28.

HCC Category Mapping

V24HCC 115, Pneumococcal Pneumonia, Empyema, Lung Abscess

0.130

ESRDHCC 115, Pneumococcal Pneumonia, Empyema, Lung Abscess

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 A20.2 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for A20.2

For A20.2to 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 A20.2 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

A20.2 is the ICD-10-CM diagnosis code for pneumonic plague. Pneumonic plague is a severe lung infection caused by the bacterium Yersinia pestis, which is transmitted through respiratory droplets or inhalation of contaminated air. This is the most dangerous form of plague and can spread from person to person, causing rapid onset of respiratory symptoms and potentially fatal complications. A20.2 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering certain zoonotic bacterial diseases (a20-a28).

Under the older CMS-HCC V24 model, A20.2 maps to Pneumococcal Pneumonia, Empyema, Lung Abscess (HCC 115) with a community, non-dual, aged base RAF weight of 0.130. 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.

Pneumonic plague is a reportable disease in most jurisdictions; ensure proper documentation of diagnosis and consider notifying public health authorities as required by law. Because A20.2 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 A20.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Pneumonic plague is a reportable disease in most jurisdictions; ensure proper documentation of diagnosis and consider notifying public health authorities as required by law
•Distinguish between pneumonic plague (A20.2) and other plague forms such as bubonic plague (A20.0) or septicemic plague (A20.7) based on clinical presentation and affected body systems

Clinical Significance

Pneumonic plague is the most severe and rapidly fatal form of Yersinia pestis infection, capable of person-to-person airborne transmission. It is a public health emergency requiring immediate isolation, notification to health authorities, and aggressive antibiotic therapy within 24 hours of symptom onset to prevent death.

Documentation Requirements

✓Clinical presentation consistent with pneumonic plague (severe pneumonia, hemoptysis, sepsis)
✓Laboratory confirmation — culture, PCR, or serology for Yersinia pestis
✓Epidemiologic link (endemic area exposure, animal contact, bioterrorism concern)
✓Chest imaging showing rapidly progressive bilateral pneumonia
✓Public health notification documentation as this is a nationally notifiable disease

Commonly Confused Codes

•A20.0 (Bubonic plague): Bubonic plague presents with lymphadenopathy (buboes); pneumonic plague specifically involves the lungs with pneumonia
•A20.7 (Septicemic plague): Septicemic plague is bloodstream infection without primary pneumonia; can overlap: code both if both documented
•J15.9 (Unspecified bacterial pneumonia): Never use generic pneumonia codes when plague pneumonia is identified