A01.03
BillableTyphoid pneumonia
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is A01.03 an HCC code?
Yes. A01.03 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 A01.03
For A01.03to 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 A01.03 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
A01.03 is the ICD-10-CM diagnosis code for typhoid pneumonia. This is a serious lung infection caused by the typhoid bacteria (Salmonella typhi) that has spread to the respiratory system. It represents a complication of typhoid fever where the infection affects the lungs and causes pneumonia. A01.03 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering intestinal infectious diseases (a00-a09).
Under the older CMS-HCC V24 model, A01.03 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.
This code should only be used when typhoid fever has specifically caused pneumonia as a documented complication; do not use for pneumonia from other causes in a typhoid patient. Because A01.03 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 A01.03 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code should only be used when typhoid fever has specifically caused pneumonia as a documented complication; do not use for pneumonia from other causes in a typhoid patient
- •Verify that the clinical documentation explicitly states the pneumonia is related to typhoid infection, as this is a specific manifestation code requiring clear causal relationship
Clinical Significance
Typhoid pneumonia represents a severe extraintestinal complication of Salmonella typhi infection, indicating systemic disease spread to the lungs. This complication significantly increases morbidity and mortality, requiring aggressive antimicrobial therapy and often intensive care management.
Documentation Requirements
- ✓Confirmed or suspected Salmonella typhi infection with documented pulmonary involvement
- ✓Chest imaging findings (X-ray or CT) showing pneumonic infiltrates
- ✓Clinical correlation establishing the causal link between typhoid fever and pneumonia
- ✓Sputum or blood culture results identifying Salmonella typhi
- ✓Respiratory symptoms (cough, dyspnea, pleuritic chest pain) in the setting of typhoid fever
Commonly Confused Codes
- •A01.00 (Typhoid fever, unspecified) — Use A01.03 only when pneumonia is a documented complication; A01.00 is for typhoid without specified organ involvement
- •J15.9 (Unspecified bacterial pneumonia) — Use A01.03 when the pneumonia is specifically caused by typhoid, not J15.9 with a separate typhoid code
- •A02.22 (Salmonella pneumonia) — A02.22 is for non-typhi Salmonella species causing pneumonia; A01.03 is specifically for S. typhi