D3A.091
BillableBenign carcinoid tumor of the thymus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D3A.091 an HCC code?
Yes. D3A.091 maps to Bladder, Colorectal, and Other Cancers under the CMS-HCC V28 risk adjustment model.
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 D3A.091
For D3A.091to 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 D3A.091 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D3A.091 is the ICD-10-CM diagnosis code for benign carcinoid tumor of the thymus. A benign hormone-producing tumor of the thymus gland, which is located in the chest behind the breastbone. D3A.091 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering benign neuroendocrine tumors (d3a).
Under the CMS-HCC V28 risk adjustment model, D3A.091 maps to Bladder, Colorectal, and Other Cancers (HCC 22) with a community, non-dual, aged base RAF weight of 0.363. D3A.091 was not retained as a payment HCC under the older V24 model, so V28 introduced or recategorized it during the 2024–2026 phase-in. 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.
Confirm the diagnosis is benign and not thymic carcinoma (C37) through pathology documentation. Because D3A.091 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 D3A.091 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm the diagnosis is benign and not thymic carcinoma (C37) through pathology documentation
- •Note that thymic carcinoid tumors may be associated with MEN syndromes - query for additional diagnoses if applicable
Clinical Significance
Benign carcinoid tumors of the thymus are rare neuroendocrine neoplasms that may be associated with Multiple Endocrine Neoplasia type 1 syndrome. Despite being classified as benign, thymic carcinoids require careful surveillance because they can occasionally exhibit more aggressive behavior than other carcinoid tumor sites.
Documentation Requirements
- ✓Documentation should include pathology confirmation of neuroendocrine differentiation with benign behavior, including mitotic rate and Ki-67 index.
- ✓Screening for Multiple Endocrine Neoplasia type 1 syndrome should be documented if clinically indicated.
- ✓Cross-sectional imaging findings and tumor size should be recorded.