B44.81
BillableAllergic bronchopulmonary aspergillosis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is B44.81 an HCC code?
Yes. B44.81 maps to Chronic Obstructive Pulmonary Disease under the CMS-HCC V28 risk adjustment model (and Fibrosis of Lung and Other Chronic Lung Disorders 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 B44.81
For B44.81 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 B44.81 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
B44.81 is the ICD-10-CM diagnosis code for allergic bronchopulmonary aspergillosis. An allergic reaction in the airways and lungs to Aspergillus fungus, causing inflammation and breathing difficulties in susceptible individuals. B44.81 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, B44.81 maps to Chronic Obstructive Pulmonary Disease (HCC 280) with a community, non-dual, aged base RAF weight of 0.334. Under the older CMS-HCC V24 model, B44.81 maps to Fibrosis of Lung and Other Chronic Lung Disorders (HCC 112) with a community, non-dual, aged base RAF weight of 0.268. 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 is an allergic/hypersensitivity response, not an invasive infection; do not code as invasive aspergillosis. Because B44.81 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 B44.81 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is an allergic/hypersensitivity response, not an invasive infection; do not code as invasive aspergillosis
- •Often associated with asthma or cystic fibrosis; review for comorbid conditions to code appropriately
Clinical Significance
Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity reaction to Aspergillus colonization in the airways, NOT an invasive infection. It primarily affects patients with asthma or cystic fibrosis and maps to a chronic lung disease HCC rather than the opportunistic infections HCC, reflecting its fundamentally different pathophysiology and resource utilization pattern.
Documentation Requirements
- ✓Elevated total IgE levels (typically >1000 IU/mL)
- ✓Positive Aspergillus-specific IgE and IgG antibodies
- ✓Central bronchiectasis on CT imaging
- ✓Peripheral blood eosinophilia documented
- ✓Underlying asthma or cystic fibrosis documented
- ✓Treatment documented: systemic corticosteroids and/or antifungal (itraconazole)
Commonly Confused Codes
- •B44.0 (Invasive pulmonary aspergillosis) - ABPA is an ALLERGIC response, not tissue invasion; completely different disease mechanism
- •B44.1 (Other pulmonary aspergillosis) - chronic colonization, not allergic hypersensitivity
- •J45.50 (Severe persistent asthma, uncomplicated) - asthma underlies ABPA but does not capture the Aspergillus hypersensitivity component
- •J67.4 (Maltworker's lung) - extrinsic allergic alveolitis from aspergillus is different from ABPA