D3A.020
BillableBenign carcinoid tumor of the appendix
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D3A.020 an HCC code?
Yes. D3A.020 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.020
For D3A.020to 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.020 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D3A.020 is the ICD-10-CM diagnosis code for benign carcinoid tumor of the appendix. A benign neuroendocrine tumor located in the appendix, a small tube-shaped organ attached to the large intestine. D3A.020 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.020 maps to Bladder, Colorectal, and Other Cancers (HCC 22) with a community, non-dual, aged base RAF weight of 0.363. D3A.020 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.
The appendix is a common site for carcinoid tumors; ensure appendix is clearly documented. Because D3A.020 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.020 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •The appendix is a common site for carcinoid tumors; ensure appendix is clearly documented
- •Distinguish from appendicitis or other appendiceal conditions
Clinical Significance
Benign carcinoid tumor of the appendix is the most common appendiceal neoplasm and the most common type of carcinoid tumor overall, frequently discovered incidentally during appendectomy for acute appendicitis. Most appendiceal carcinoids are small (less than 1cm), well-differentiated, and carry an excellent prognosis after simple appendectomy. Tumors greater than 2cm or with mesoappendiceal invasion may require right hemicolectomy.
Documentation Requirements
- ✓Surgical pathology from appendectomy documenting a well-differentiated neuroendocrine tumor with tumor size, depth of invasion, margin status, and Ki-67 proliferative index.
- ✓Document whether the tumor was discovered incidentally during appendectomy or was clinically suspected preoperatively.
- ✓For tumors greater than 1cm, note whether a completion right hemicolectomy was performed or recommended.
Commonly Confused Codes
- •C7A.020 (malignant carcinoid of appendix) is for tumors with malignant features (larger size, invasion, positive margins)
- •D3A.021 (cecum) is for tumors at the appendiceal-cecal junction or cecum proper
- •D37.3 (appendix, uncertain behavior) may apply when the benign vs. malignant distinction is unclear
- •C18.1 (malignant neoplasm of appendix) covers non-carcinoid appendiceal malignancies.