B44.2
BillableTonsillar aspergillosis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is B44.2 an HCC code?
Yes. B44.2 maps to Opportunistic Infections under the CMS-HCC V28 risk adjustment model (and Opportunistic Infections under V24).
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 B44.2
For B44.2 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 B44.2 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
B44.2 is the ICD-10-CM diagnosis code for tonsillar aspergillosis. A fungal infection of the tonsils caused by Aspergillus mold, which can cause inflammation and infection in the throat area. B44.2 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering mycoses (b35-b49).
Under the CMS-HCC V28 risk adjustment model, B44.2 maps to Opportunistic Infections (HCC 6) with a community, non-dual, aged base RAF weight of 0.439. Under the older V24 model, B44.2 mapped to the same category but with a base RAF weight of 0.440 — 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.
Confirm the infection is specifically in the tonsillar tissue and not a secondary manifestation of pulmonary aspergillosis. Because B44.2 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 B44.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm the infection is specifically in the tonsillar tissue and not a secondary manifestation of pulmonary aspergillosis
- •Document whether the patient has immunocompromise, as this affects treatment and prognosis
Clinical Significance
Tonsillar aspergillosis is an uncommon form of Aspergillus infection localized to the tonsillar tissue, typically occurring in immunocompromised patients. As an opportunistic fungal infection, it signals significant immune dysfunction and carries the same high RAF weight as other aspergillosis codes, making it important for risk adjustment capture.
Documentation Requirements
- ✓Biopsy or culture confirmation of Aspergillus from tonsillar tissue
- ✓Documented immunocompromised state (neutropenia, transplant, HIV)
- ✓Physical exam findings: tonsillar enlargement, necrotic tissue, pseudomembrane
- ✓Symptoms documented: sore throat, dysphagia, odynophagia
- ✓Evidence that infection is localized to tonsils versus disseminated disease