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C7A.8 ICD-10-CM Code: Other malignant neuroendocrine tumors

C7A.8 maps to CMS-HCC V28 21. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupC7A.8

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neuroendocrine tumors (C7A)

C7A.8

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Other malignant neuroendocrine tumors

A rare cancer arising from hormone-producing cells that does not fit into the standard carcinoid tumor categories.

Buddy the Bee presenting code insight

Buddy Insight

Other malignant neuroendocrine tumors is a residual category for malignant neuroendocrine neoplasms that do not classify as carcinoid tumors or poorly differentiated neuroendocrine carcinomas.

OverviewRisk ModelsCode BookDocumentationAuditNotesEdition comparison

CMS-HCC V28

HCC 21

Coefficient HCC 21: 0.671 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Historical

Not used for CY2026 payment

ACA/HHS

HCC 012

Code-level coefficient reference

ESRD/PACE

HCC 12

Code-level coefficient reference

RXHCC

HCC 22

Code-level coefficient reference

Code Book Path

Official
C7AMalignant neuroendocrine tumorsC7A.8Other malignant neuroendocrine tumors

Inclusion Terms

Official

No inclusion terms are included in this display for C7A.8. Check the code and parent instructions in the Code Book.

Excludes 2

Official
  • malignant pancreatic islet cell tumors (C25.4)Inherited from C7A
  • Merkel cell carcinoma (C4A.-)Inherited from C7A

Related Codes

Official
C7A.0Malignant carcinoid tumorsC7A.1Malignant poorly differentiated neuroendocrine tumors

Includes

Official

No Includes notes are included in this display for C7A.8. Check the code and parent instructions in the Code Book.

Excludes 1

Official

No Excludes 1 notes are included in this display for C7A.8. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for C7A.8. Check the code and parent instructions in the Code Book.

Use Additional

Official
  • code to identify any associated endocrine syndrome, such as:Inherited from C7A
  • carcinoid syndrome (E34.00)Inherited from C7A

Code Also

Official
  • any associated multiple endocrine neoplasia [MEN] syndromes (E31.2-)Inherited from C7A

Buddy Documentation Tip

HCC Buddy guidance
Pathology report with immunohistochemistry confirming neuroendocrine differentiation
Specific tumor type classification (paraganglioma, MiNEN, etc.)
Documentation that the tumor does not meet criteria for carcinoid (C7A.0) or poorly differentiated neuroendocrine carcinoma (C7A.1)
Primary site of origin

MEAT Support

HCC Buddy guidance
Pathology report with immunohistochemistry confirming neuroendocrine differentiation
Specific tumor type classification (paraganglioma, MiNEN, etc.)
Documentation that the tumor does not meet criteria for carcinoid (C7A.0) or poorly differentiated neuroendocrine carcinoma (C7A.1)
Primary site of origin

Audit Caution

HCC Buddy guidance
Using this code as a catch-all for any neuroendocrine tumor without first ruling out carcinoid or poorly differentiated classification
Not reviewing pathology reports carefully to determine whether a more specific code applies
Failing to document the specific neuroendocrine tumor subtype, limiting clinical utility of the code
Confusing with neuroendocrine tumors of uncertain behavior (D-codes) when malignancy is not confirmed

Common Mistakes

HCC Buddy guidance
C7A.0 series — Malignant carcinoid tumors: Use C7A.0 codes for confirmed carcinoid-type neuroendocrine tumors with specific site
C7A.1 — Malignant poorly differentiated neuroendocrine tumors: Use when pathology confirms poor differentiation/Grade 3
C7A.098 — Malignant carcinoid tumors of other sites: C7A.098 is for carcinoid histology at unusual sites; C7A.8 is for non-carcinoid neuroendocrine tumors
D44.7 — Neoplasm of uncertain behavior of aortic body and other paraganglia: Use for paragangliomas of uncertain behavior

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is C7A.8 an HCC code?

Yes. C7A.8 (Other malignant neuroendocrine tumors) maps to HCC 21, Lymphoma and Other Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.671. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: C7A.8 is billable and maps to V28 HCC 21, Lymphoma and Other Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code
C7A.8
Description
Other malignant neuroendocrine tumors
HCC (V28)
HCC 21 — Lymphoma and Other Cancers
RAF reference coefficient
0.671
Billable
Yes
Payment year
2026

HCC Category Mapping

V28HCC 21, Lymphoma and Other Cancers
0.671
ESRDHCC 12, Breast/Prostate/and Other Cancers and Tumors
Not separately weighted
RxHCCHCC 22, Prostate, Breast, Bladder, and Other Cancers and Tumors
Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work C7A.8 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C7A.8

For C7A.8, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

  • 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

Coder workflow notes

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What This Code Means

C7A.8 is the ICD-10-CM diagnosis code for other malignant neuroendocrine tumors. A rare cancer arising from hormone-producing cells that does not fit into the standard carcinoid tumor categories. C7A.8 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neuroendocrine tumors (c7a).

Under the CMS-HCC V28 risk adjustment model, C7A.8 maps to Lymphoma and Other Cancers (HCC 21) with a source-labeled community, non-dual, aged reference coefficient of 0.671. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

This is a residual category; thoroughly document the tumor type and site to justify use of this code over more specific options. For C7A.8, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for C7A.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • •This is a residual category; thoroughly document the tumor type and site to justify use of this code over more specific options
  • •Review pathology reports to confirm neuroendocrine origin and rule out other malignancies

Clinical Significance

Other malignant neuroendocrine tumors is a residual category for malignant neuroendocrine neoplasms that do not classify as carcinoid tumors or poorly differentiated neuroendocrine carcinomas. This includes entities such as paragangliomas with malignant behavior, mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN), and other rare neuroendocrine tumor types. These tumors require specialized pathologic evaluation and multidisciplinary oncologic management.

Documentation Requirements

  • ✓Pathology report with immunohistochemistry confirming neuroendocrine differentiation
  • ✓Specific tumor type classification (paraganglioma, MiNEN, etc.)
  • ✓Documentation that the tumor does not meet criteria for carcinoid (C7A.0) or poorly differentiated neuroendocrine carcinoma (C7A.1)
  • ✓Primary site of origin
  • ✓Functional status (hormone-producing vs non-functional)
  • ✓Staging and treatment plan

Commonly Confused Codes

  • •C7A.0 series: Malignant carcinoid tumors: Use C7A.0 codes for confirmed carcinoid-type neuroendocrine tumors with specific site
  • •C7A.1: Malignant poorly differentiated neuroendocrine tumors: Use when pathology confirms poor differentiation/Grade 3
  • •C7A.098: Malignant carcinoid tumors of other sites: C7A.098 is for carcinoid histology at unusual sites; C7A.8 is for non-carcinoid neuroendocrine tumors
  • •D44.7: Neoplasm of uncertain behavior of aortic body and other paraganglia: Use for paragangliomas of uncertain behavior

Child Codes

C7A.0Malignant carcinoid tumors
C7A.1Malignant poorly differentiated neuroendocrine tumors
HCC 21
C7A.8Other malignant neuroendocrine tumors
HCC 21

Code Hierarchy

└C7AMalignant neuroendocrine tumors└C7A.8Other malignant neuroendocrine tumors
└C7A.8Other malignant neuroendocrine tumors

Also searched as

  • C7A 8
  • C7A8

For C7A.8, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

C7A.8 maps to CMS-HCC V28 category 21, Lymphoma and Other Cancers. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works. The mapping identifies a payment HCC category for C7A.8. Review its source-labeled HCC coefficient above, check the RAF Calculator with complete member context for CMS-HCC V28 PY2026, and confirm the documentation the chart needs before the code is submitted. HCC Buddy shows no RAF score unless every required source and calculation check passes.

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