C72.21 maps to CMS-HCC V28 20. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

HCC Buddy Code Card

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Code lookupC72.21

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of eye, brain and other parts of central nervous system (C69-C72)

C72.21

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

Malignant neoplasm of right olfactory nerve

A malignant (cancerous) tumor of the right olfactory nerve, which is the nerve responsible for the sense of smell on the right side.

Buddy Insight

Malignant neoplasm of the right olfactory nerve is a rare cranial nerve malignancy typically presenting as esthesioneuroblastoma.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 20

Lung and Other Severe Cancers

Coefficient HCC 20: 1.136 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 009

HHS-HCC 009 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 10

Lymphoma and Other Cancers

Code-level coefficient reference

RXHCC

Mapped

HCC 22

Prostate, Breast, Bladder, an...

Code-level coefficient reference

Code Book Path

Official

C72Malignant neoplasm of spinal cord, cranial nerves and other parts of central nervous system C72.2Malignant neoplasm of olfactory nerve C72.21Malignant neoplasm of right olfactory nerve

Inclusion Terms

Official

Malignant neoplasm of olfactory bulbInherited from C72.2

Excludes 2

Official

No Excludes 2 notes are included in this display for C72.21. Check the code and parent instructions in the Code Book.

Related Codes

Official

C72.20Malignant neoplasm of unspecified olfactory nerve C72.22Malignant neoplasm of left olfactory nerve

Includes

Official

No Includes notes are included in this display for C72.21. Check the code and parent instructions in the Code Book.

Excludes 1

Official

malignant neoplasm of meninges (C70.-)Inherited from C72
malignant neoplasm of peripheral nerves and autonomic nervous system (C47.-)Inherited from C72

Code First

Official

No Code First sequencing instructions are included in this display for C72.21. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for C72.21. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for C72.21. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Pathology report with histological confirmation of malignancy

Clear documentation of right-sided olfactory nerve involvement

Imaging confirming laterality and extent of disease

Treatment status (active treatment, surveillance, or history of)

MEAT Support

HCC Buddy guidance

Pathology report with histological confirmation of malignancy

Clear documentation of right-sided olfactory nerve involvement

Imaging confirming laterality and extent of disease

Treatment status (active treatment, surveillance, or history of)

Audit Caution

HCC Buddy guidance

Transposing right and left laterality — always verify against operative/imaging reports

Using unspecified code C72.20 when right side is clearly documented

Confusing olfactory nerve (CN I) tumors with optic nerve (CN II) tumors in the anterior cranial fossa

Not capturing this code annually when patient is under active surveillance

Common Mistakes

HCC Buddy guidance

C72.22 — Malignant neoplasm of left olfactory nerve: Laterality error; verify right vs. left in documentation

C72.20 — Malignant neoplasm of unspecified olfactory nerve: Use C72.21 when right side is documented

C30.0 — Malignant neoplasm of nasal cavity: Nasal cavity tumors are not nerve origin tumors

C72.31 — Malignant neoplasm of right optic nerve: Different cranial nerve entirely; verify nerve of origin

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 C72.21 an HCC code?

Yes. C72.21 (Malignant neoplasm of right olfactory nerve) maps to HCC 20, Lung and Other Severe Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.136. 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: C72.21 is billable and maps to V28 HCC 20, Lung and Other Severe Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C72.21
Description: Malignant neoplasm of right olfactory nerve
HCC (V28): HCC 20 — Lung and Other Severe Cancers
RAF reference coefficient: 1.136
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 20, Lung and Other Severe Cancers

1.136

ESRDHCC 10, Lymphoma and Other Cancers

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 C72.21 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C72.21

For C72.21, 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

C72.21 is the ICD-10-CM diagnosis code for malignant neoplasm of right olfactory nerve. A malignant (cancerous) tumor of the right olfactory nerve, which is the nerve responsible for the sense of smell on the right side. C72.21 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of eye, brain and other parts of central nervous system (c69-c72).

Under the CMS-HCC V28 risk adjustment model, C72.21 maps to Lung and Other Severe Cancers (HCC 20) with a source-labeled community, non-dual, aged reference coefficient of 1.136. 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 code specifies the right side; use C72.22 for left side and verify laterality in documentation. For C72.21, 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 C72.21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This code specifies the right side; use C72.22 for left side and verify laterality in documentation
•Olfactory nerve tumors are rare; confirm diagnosis and ensure proper documentation of nerve origin

Clinical Significance

Malignant neoplasm of the right olfactory nerve is a rare cranial nerve malignancy typically presenting as esthesioneuroblastoma. Right-sided laterality documentation is important for surgical planning and radiation field targeting. This code represents the highest specificity for this anatomical site and should be used whenever documentation confirms right-sided involvement.

Documentation Requirements

✓Pathology report with histological confirmation of malignancy
✓Clear documentation of right-sided olfactory nerve involvement
✓Imaging confirming laterality and extent of disease
✓Treatment status (active treatment, surveillance, or history of)
✓Staging information and any intracranial or orbital extension

Commonly Confused Codes

•C72.22: Malignant neoplasm of left olfactory nerve: Laterality error; verify right vs. left in documentation
•C72.20: Malignant neoplasm of unspecified olfactory nerve: Use C72.21 when right side is documented
•C30.0: Malignant neoplasm of nasal cavity: Nasal cavity tumors are not nerve origin tumors
•C72.31: Malignant neoplasm of right optic nerve: Different cranial nerve entirely; verify nerve of origin