A20.2
BillablePneumonic plague
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
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
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.
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.
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 0.339. 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