ICD-10 C01
Billable / Specific HCC v28: 11Malignant neoplasm of base of tongue
About ICD-10-CM C01
ICD-10-CM code C01 represents Malignant neoplasm of base of tongue. This is a billable/specific code in the Neoplasms chapter (block C01). The 2026 edition of ICD-10-CM C01 became effective on October 1, 2025.
Coding Tips for C01
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
C01 is a CMS-HCC v28 risk-adjustment code (category 11). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under C01. Per CMS ICD-10-CM Tabular 2026.
- Malignant neoplasm of dorsal surface of base of tongue
- Malignant neoplasm of fixed part of tongue NOS
- Malignant neoplasm of posterior third of tongue
Use Additional Code
When coding C01, also report these additional codes when applicable.
- code to identify:
- alcohol abuse and dependence (F10.-)
- history of tobacco dependence (Z87.891)
- tobacco dependence (F17.-)
- tobacco use (Z72.0)
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Medicare LCD Coverage for C01
Local Coverage Determinations (LCDs) from CMS MACs that list C01 as a covered diagnosis.
Showing top 10 of 983 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing C01.
3 Cigna
5 Medicare
CPT Codes Commonly Billed with C01
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 63621 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- 61800 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- 77373 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- G0339 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- 77372 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- G0563 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- 77435 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- 77371 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- G0340 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
- 61798 CMS LCD: Billing and Coding: Stereotactic Radiation Therapy: Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) CMS LCD
Convert C01 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| C01 | 1410 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To C01
Other codes in section C00-C14 (Malignant neoplasms of lip, oral cavity and pharynx).
ICD-10 C01, Billing FAQ
Is ICD-10 code C01 billable? +
Yes, C01 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to C01? +
ICD-10 C01 includes: Malignant neoplasm of dorsal surface of base of tongue; Malignant neoplasm of fixed part of tongue NOS; Malignant neoplasm of posterior third of tongue.
Does C01 affect Medicare Advantage HCC risk adjustment? +
Yes. C01 maps to CMS-HCC v28 category 11. Capture this diagnosis annually for accurate Medicare Advantage risk score.
What CPT codes are commonly billed with C01? +
Procedures frequently paired with C01 include: 63621, 61800, 77373, G0339, 77372.
What ICD-9 codes does C01 map to? +
Per CMS GEMs, C01 maps to ICD-9 codes: 1410. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on July 16, 2026.
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