ICD-10-CM 2027 diagnosis code
C73Malignant neoplasm of thyroid gland
C73 is a valid, billable ICD-10-CM code for malignant neoplasm of thyroid gland. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Looking up by condition? See ICD-10 code for Wuchernde Struma Langhans.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About C73
C73 is the ICD-10-CM diagnosis code for malignant neoplasm of thyroid gland. It belongs to block C73-C75 (malignant neoplasms of thyroid and other endocrine glands) and chapter 2 (neoplasms). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Use an additional code to identify any functional activity.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 643 (Endocrine Disorders with MCC, relative weight 1.6139), DRG 644 (Endocrine Disorders with CC, relative weight 1.0044) and DRG 645 (Endocrine Disorders without CC/MCC, relative weight 0.7459), in Pre-MDC and MDC 10 (Endocrine, Nutritional and Metabolic Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 193 (malignant neoplasm of thyroid gland).
Coding notes
- code to identify any functional activity
Notes that apply from higher levels
Instructions written at a parent level also apply to C73.
Broader instructions also apply from Chapter 2: Neoplasms.
Alphabetic index entries
30 entriesTerms in the official ICD-10-CM index that lead to C73.
- Adenocarcinoma › follicular › with papillary
- Adenocarcinoma › follicular › moderately differentiated
- Adenocarcinoma › follicular › trabecular
- Adenocarcinoma › follicular › unspecified site
- Adenocarcinoma › follicular › well differentiated
- Adenocarcinoma › Hurthle cell
- Adenocarcinoma › nonencapsulated sclerosing
- Adenocarcinoma › papillary › with follicular
- Adenocarcinoma › papillary › follicular variant
- Carcinoma (malignant) › C cell › unspecified site
- Carcinoma (malignant) › follicular › with papillary (mixed)
- Carcinoma (malignant) › follicular › moderately differentiated
- Carcinoma (malignant) › follicular › pure follicle
- Carcinoma (malignant) › follicular › trabecular
- Carcinoma (malignant) › follicular › unspecified site
- Carcinoma (malignant) › follicular › well differentiated
- Carcinoma (malignant) › Hurthle cell
- Carcinoma (malignant) › medullary › with › amyloid stroma › unspecified site
- Carcinoma (malignant) › nonencapsulated sclerosing
- Carcinoma (malignant) › papillary › with follicular (mixed)
- Carcinoma (malignant) › papillary › follicular variant
- Carcinoma (malignant) › parafollicular cell › unspecified site
- Carcinoma (malignant) › solid › with amyloid stroma › unspecified site
- Goiter (plunging) (substernal) › cancerous
- Goiter (plunging) (substernal) › malignant
- Hurthle cell › adenocarcinoma
- Hurthle cell › carcinoma
- Tumor › Hurthle cell (benign) › malignant
- Tumor › nonencapsulated sclerosing
- Wuchernde Struma Langhans
Table of Drugs & Neoplasms entries
- Neoplasm, neoplastic › thyroglossal duct — Malignant Primary
- Neoplasm, neoplastic › thyroid (gland) — Malignant Primary
Codes whose notes reference C73
- C75Excludes1
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC PRE · Pre-MDC
MDC 10 · Endocrine, Nutritional and Metabolic Diseases and Disorders
ICD-9-CM equivalent
Converter →- 193Malignant neoplasm of thyroid glandexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about C73
Is C73 billable?
- Yes. C73 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can C73 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict C73 as a principal diagnosis.
Is C73 a CC or MCC?
- No. C73 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does C73 group to?
- C73 is used in the MS-DRG v44.0 logic for MS-DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC), MS-DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC), MS-DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC), MS-DRG 643 (Endocrine Disorders with MCC), MS-DRG 644 (Endocrine Disorders with CC) and MS-DRG 645 (Endocrine Disorders without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for C73?
- The CMS General Equivalence Mappings map C73 to ICD-9-CM 193.