B44.1 ICD-10-CM Code: Other pulmonary aspergillosis
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Mycoses (B35-B49)
B44.1
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceOther pulmonary aspergillosis
A fungal infection of the lungs caused by Aspergillus, a common mold found in the environment that can cause various respiratory problems.
Buddy Insight
Other pulmonary aspergillosis encompasses non-invasive forms including chronic pulmonary aspergillosis and aspergilloma (fungus ball).
CMS-HCC V28
MappedHCC 6
RAF 0.439
CMS-HCC V24
MappedHCC 6
RAF 0.440
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 6
RAF 0.0
RXHCC
MappedHCC 5
RAF 0.0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for B44.1 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for B44.1 in this effective period.
Related Child Codes
Includes
Official- aspergilloma
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for B44.1 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for B44.1 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for B44.1 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for B44.1 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 B44.1 an HCC code?
Yes. B44.1 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 B44.1
For B44.1to 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 B44.1 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
B44.1 is the ICD-10-CM diagnosis code for other pulmonary aspergillosis. A fungal infection of the lungs caused by Aspergillus, a common mold found in the environment that can cause various respiratory problems. B44.1 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, B44.1 maps to Opportunistic Infections (HCC 6) with a community, non-dual, aged base RAF weight of 0.439. Under the older V24 model, B44.1 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.
Specify the type of pulmonary aspergillosis if documented (chronic form, acute form, or other variants). Because B44.1 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 B44.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Specify the type of pulmonary aspergillosis if documented (chronic form, acute form, or other variants)
- •Review clinical notes to determine if this is invasive aspergillosis or a non-invasive form, as this affects severity coding
Clinical Significance
Other pulmonary aspergillosis encompasses non-invasive forms including chronic pulmonary aspergillosis and aspergilloma (fungus ball). While less acutely life-threatening than invasive disease, these conditions require ongoing management and surveillance. The code still maps to the high-value opportunistic infections HCC, reflecting the immunocompromised context in which these infections typically occur.
Documentation Requirements
- ✓Imaging findings specific to the form: fungus ball in cavity (aspergilloma), progressive cavitation (chronic)
- ✓Culture or serologic confirmation of Aspergillus species
- ✓Distinction from invasive disease documented (tissue invasion absent)
- ✓Underlying structural lung disease documented (tuberculosis scarring, sarcoidosis, cavitary disease)
- ✓Aspergillus-specific IgG levels if chronic pulmonary aspergillosis
Commonly Confused Codes
- •B44.0 (Invasive pulmonary aspergillosis) - invasive form penetrates tissue and occurs in immunosuppressed patients; B44.1 is non-invasive
- •B44.81 (Allergic bronchopulmonary aspergillosis) - ABPA is an allergic/immune response, not infection; maps to different HCC
- •J84.10 (Pulmonary fibrosis, unspecified) - fibrosis secondary to chronic aspergillosis should still be coded with B44.1