B48.8
BillableOther specified mycoses
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is B48.8 an HCC code?
Yes. B48.8 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 B48.8
For B48.8to 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 B48.8 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
B48.8 is the ICD-10-CM diagnosis code for other specified mycoses. A fungal infection caused by other specified fungi not classified elsewhere, such as uncommon or emerging fungal pathogens. B48.8 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, B48.8 maps to Opportunistic Infections (HCC 6) with a community, non-dual, aged base RAF weight of 0.381. Under the older V24 model, B48.8 mapped to the same category but with a base RAF weight of 0.424 — 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.
Use this code only when the specific fungal organism doesn't fit other B48 categories. Because B48.8 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 B48.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the specific fungal organism doesn't fit other B48 categories
- •Document the specific fungal organism identified in the medical record for clarity
Clinical Significance
Other specified mycoses is a residual category for documented fungal infections that do not have their own specific ICD-10-CM code. This includes rare organisms like Adiaspiromycosis, Fusarium infections, or other emerging fungal pathogens. Despite being a catch-all code, it maps to the high-value opportunistic infections HCC, reflecting the clinical significance of these unusual infections.
Documentation Requirements
- ✓Specific fungal organism identified and documented in the medical record
- ✓Culture, histopathology, or molecular testing confirming the fungal species
- ✓Site of infection documented
- ✓Immunocompromised status documented when present
- ✓Treatment regimen and clinical response documented
Commonly Confused Codes
- •B49 (Unspecified mycosis) - use only when the organism is completely unidentified; B48.8 is for identified but non-classified organisms
- •B48.4 (Penicillosis) - Talaromyces marneffei has its own code; do not use B48.8
- •B44.89 (Other forms of aspergillosis) - Aspergillus infections go to the B44 family, not B48.8