D81.30
BillableAdenosine deaminase deficiency, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D81.30 an HCC code?
Yes. D81.30 maps to Common Variable and Combined Immunodeficiencies under the CMS-HCC V28 risk adjustment model (and Disorders of Immunity 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 D81.30
For D81.30to 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 D81.30 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D81.30 is the ICD-10-CM diagnosis code for adenosine deaminase deficiency, unspecified. A deficiency of the enzyme adenosine deaminase that helps break down harmful substances, but the specific severity or type is not specified. D81.30 sits in the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89), within the section covering certain disorders involving the immune mechanism (d80-d89).
Under the CMS-HCC V28 risk adjustment model, D81.30 maps to Common Variable and Combined Immunodeficiencies (HCC 114) with a community, non-dual, aged base RAF weight of 2.262. Under the older CMS-HCC V24 model, D81.30 maps to Disorders of Immunity (HCC 47) with a community, non-dual, aged base RAF weight of 0.665. 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 only when documentation does not specify whether this causes SCID or other adenosine deaminase deficiency. Because D81.30 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 D81.30 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use only when documentation does not specify whether this causes SCID or other adenosine deaminase deficiency
- •Review enzyme level testing to determine if more specific coding is appropriate
Clinical Significance
Adenosine deaminase deficiency, unspecified, indicates a documented deficiency of the adenosine deaminase enzyme without specification of whether it causes severe combined immunodeficiency or a milder immunologic phenotype. Adenosine deaminase is critical for purine metabolism, and its deficiency leads to accumulation of toxic metabolites that selectively destroy lymphocytes.
Documentation Requirements
- ✓Documentation must include enzyme activity levels confirming adenosine deaminase deficiency, the clinical severity of immune impairment, lymphocyte subset analysis, and whether the condition meets criteria for SCID or presents with a milder phenotype.
- ✓Query the provider to determine if the deficiency causes SCID (D81.31) or is a partial/delayed-onset form (D81.39) for more specific coding.
Commonly Confused Codes
- •D81.31 (severe combined immunodeficiency due to adenosine deaminase deficiency, the most severe form), D81.32 (adenosine deaminase 2 deficiency, a distinct enzyme with different clinical features), D81.39 (other adenosine deaminase deficiency for partial or delayed-onset forms), D81.5 (purine nucleoside phosphorylase deficiency, a different purine metabolism enzyme).