2027 ICD-10-CM Diagnosis Code C75.0Malignant neoplasm of parathyroid gland
ICD-10-CM Codes›C00–D49›C73-C75›C75
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 23
- Chronic Condition
C75.0 is a billable ICD-10-CM diagnosis code for malignant neoplasm of parathyroid gland. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 643 through 645. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 3 closely related codes. Coders also document this condition as adenocarcinoma of parathyroid gland. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Endocrine system cancers - parathyroid.
For Medicare Advantage risk adjustment, C75.0 maps to CMS-HCC Category 23 (Prostate, Breast, and Other Cancers and Tumors) under the V28 model, adding a risk factor of about 0.186 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C75.0 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adenocarcinoma of parathyroid gland
- Malignant neoplasm of parathyroid gland
- Parathyroid carcinoma
- Primary adenocarcinoma of parathyroid gland
- Primary malignant neoplasm of parathyroid gland
- Primary parathyroid carcinoma
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C75.0: its own notes plus those printed at C75 and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- malignant carcinoid tumors (C7A.0-)
- malignant neoplasm of adrenal gland (C74.-)
- malignant neoplasm of endocrine pancreas (C25.4)
- malignant neoplasm of islets of Langerhans (C25.4)
- malignant neoplasm of ovary (C56.-)
- malignant neoplasm of testis (C62.-)
- malignant neoplasm of thymus (C37)
- malignant neoplasm of thyroid gland (C73)
- malignant neuroendocrine tumors (C7A.-)
Notes
General instructions on how these codes are used.
- Functional activity
- All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
- Morphology [Histology]
- Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
- Primary malignant neoplasms overlapping site boundaries
- A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
- Malignant neoplasm of ectopic tissue
- Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name C75.0, its category, or a range that includes it.
Applicable To 2
These notes mention C75.0.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Adenocarcinoma See Also: Neoplasm, malignant, by site;
water-clear cell C75.0
Carcinoma (malignant) See Also: Neoplasm, by site, malignant;
water-clear cell C75.0
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Malignant Parathyroid Gland Neoplasm
a primary or metastatic malignant neoplasm affecting the parathyroid glands.
Table of NeoplasmsClinical
Patient EducationClinical
Parathyroid cancer
Parathyroid cancer is a rare cancer that usually affects people in their forties or fifties and occurs in one of the four parathyroid glands. The parathyroid glands are located in the neck and secrete parathyroid hormone, which enhances the release of calcium into the blood.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C75.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C75.0Overview
What is the ICD-10 code for malignant neoplasm of parathyroid gland?
The ICD-10-CM code for malignant neoplasm of parathyroid gland is C75.0 (sometimes written as C750). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C75.0 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of parathyroid gland on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C75.0 group to?
When malignant neoplasm of parathyroid gland is the principal diagnosis on an inpatient stay, it groups to MS-DRG 644, 645, 643, with relative weights from 0.7461 to 1.6138 depending on complications. Higher weights mean higher Medicare reimbursement.
Is C75.0 a CC or MCC?
CMS lists C75.0 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 3 closely related codes in its exclusion list.
Can C75.0 be reported with a code from C7A.0?
Not as a rule. The Excludes1 note at C75, which applies to C75.0, lists "malignant carcinoid tumors (C7A.0-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is C75.0?
C75.0 (malignant neoplasm of parathyroid gland) maps to CMS-HCC Category 23 (Prostate, Breast, and Other Cancers and Tumors), commonly written as HCC 23, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 12 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 22.
Does C75.0 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C75.0 adds a risk adjustment factor of about 0.186 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.186 to 0.237 depending on the payment segment). A more severe related category (HCC 17, HCC 18, HCC 19, HCC 20, HCC 21, and HCC 22) supersedes it when both are reported. See the full factor table on the HCC 23 category page.
