E85.81
BillableLight chain (AL) amyloidosis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E85.81 an HCC code?
Yes. E85.81 maps to Glycogen/Amino-Acid/Other Metabolic Disorders under the CMS-HCC V28 risk adjustment model (and Other Significant Endocrine and Metabolic 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 E85.81
For E85.81 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 E85.81 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E85.81 is the ICD-10-CM diagnosis code for light chain (al) amyloidosis. A disease where abnormal light chain proteins accumulate in organs and tissues, causing damage and dysfunction. This is a type of amyloidosis that primarily affects the heart, kidneys, and nervous system. E85.81 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
Under the CMS-HCC V28 risk adjustment model, E85.81 maps to Glycogen/Amino-Acid/Other Metabolic Disorders (HCC 50) with a community, non-dual, aged base RAF weight of 0.289. Under the older CMS-HCC V24 model, E85.81 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.230. 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 organ system affected when documented (cardiac, renal, or neurologic involvement). Because E85.81 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 E85.81 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Specify the organ system affected when documented (cardiac, renal, or neurologic involvement)
- •Light chain amyloidosis is also known as AL amyloidosis; use this code when the diagnosis specifies light chain type
Clinical Significance
Light chain (AL) amyloidosis is the most common form of systemic amyloidosis, caused by misfolded immunoglobulin light chains from an underlying plasma cell dyscrasia. It commonly affects the heart, kidneys, liver, and nervous system, and carries significant morbidity and mortality. Accurate coding is critical for treatment planning with chemotherapy regimens.
Documentation Requirements
- ✓Confirmed AL amyloidosis diagnosis (tissue biopsy with immunohistochemistry or mass spectrometry showing light chain deposits)
- ✓Identification of underlying plasma cell disorder (monoclonal gammopathy, multiple myeloma)
- ✓Affected organ systems and staging (cardiac biomarkers, proteinuria, NT-proBNP, troponin)
- ✓Free light chain assay results (kappa/lambda ratio)
- ✓Current treatment regimen (bortezomib-based, daratumumab, stem cell transplant evaluation)
- ✓Organ response and hematologic response assessment
Commonly Confused Codes
- •E85.82 — Wild-type transthyretin-related (ATTR) amyloidosis: different protein (transthyretin, not light chains)
- •E85.3 — Secondary systemic amyloidosis: reactive AA amyloidosis from chronic inflammation, not plasma cell disease
- •C90.00 — Multiple myeloma: may be the underlying cause; code both when applicable
- •E85.1 — Neuropathic heredofamilial amyloidosis: hereditary form, not acquired