ICD-10 C73
Billable / Specific HCC v28: 12Malignant neoplasm of thyroid gland
About ICD-10-CM C73
ICD-10-CM code C73 represents Malignant neoplasm of thyroid gland. This is a billable/specific code in the chapter (block C73). The 2026 edition of ICD-10-CM C73 became effective on October 1, 2025.
Coding Tips for C73
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
C73 is a CMS-HCC v28 risk-adjustment code (category 12). 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.
Use Additional Code
When coding C73, also report these additional codes when applicable.
- code to identify any functional activity
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 C73
Local Coverage Determinations (LCDs) from CMS MACs that list C73 as a covered diagnosis.
Showing top 10 of 1,420 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing C73.
1 Aetna
2 Cigna
5 Medicare
CPT Codes Commonly Billed with C73
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 76942 Ultrasound-guided thyroid biopsy — thyroid nodule, multinodular goiter, hyperthyroidism, thyroiditis, thyroid cancer, thyroid neoplasm, lymphadenopathy, abnormal thyroid function Endocrinology
- 95926 CMS LCD: Billing and Coding: Somatosensory Testing CMS LCD
- 95925 CMS LCD: Billing and Coding: Somatosensory Testing CMS LCD
- 95938 CMS LCD: Billing and Coding: Somatosensory Testing CMS LCD
- 95927 CMS LCD: Billing and Coding: Somatosensory Testing CMS LCD
- 36226 CMS LCD: Billing and Coding: Thoracic Aortography and Carotid, Vertebral, and Subclavian Angiography CMS LCD
- 36228 CMS LCD: Billing and Coding: Thoracic Aortography and Carotid, Vertebral, and Subclavian Angiography CMS LCD
- 36225 CMS LCD: Billing and Coding: Thoracic Aortography and Carotid, Vertebral, and Subclavian Angiography CMS LCD
- 36224 CMS LCD: Billing and Coding: Thoracic Aortography and Carotid, Vertebral, and Subclavian Angiography CMS LCD
- 36223 CMS LCD: Billing and Coding: Thoracic Aortography and Carotid, Vertebral, and Subclavian Angiography CMS LCD
Convert C73 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 |
|---|---|---|
| C73 | 193 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To C73
Other codes in section C73-C75 (Malignant neoplasms of thyroid and other endocrine glands).
ICD-10 C73, Billing FAQ
Is ICD-10 code C73 billable? +
Yes, C73 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Does C73 affect Medicare Advantage HCC risk adjustment? +
Yes. C73 maps to CMS-HCC v28 category 12. Capture this diagnosis annually for accurate Medicare Advantage risk score.
What CPT codes are commonly billed with C73? +
Procedures frequently paired with C73 include: 76942, 95926, 95925, 95938, 95927.
What ICD-9 codes does C73 map to? +
Per CMS GEMs, C73 maps to ICD-9 codes: 193. 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 June 1, 2026.
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